diff --git a/include/GLFW/glfw3.h b/include/GLFW/glfw3.h
index 8129d2fa..ca8e1e87 100644
--- a/include/GLFW/glfw3.h
+++ b/include/GLFW/glfw3.h
@@ -5845,16 +5845,31 @@ GLFWAPI void glfwSetClipboardString(GLFWwindow* window, const char* string);
  */
 GLFWAPI const char* glfwGetClipboardString(GLFWwindow* window);
 
-typedef struct GLFWtheme
-{
-    int baseTheme; // light/dark
-    int flags;
-    unsigned char color[4];
-} GLFWtheme;
+typedef struct GLFWtheme GLFWtheme;
 
-#define GLFW_BASE_THEME_DEFAULT 0
-#define GLFW_BASE_THEME_LIGHT 1
-#define GLFW_BASE_THEME_DARK 2
+typedef struct _GLFWtheme
+{
+    int variation; // light/dark
+    int flags;
+    unsigned char color[4]; // TODO: change to 128 bit (4 floats) to support wider gamuts.
+} _GLFWtheme;
+
+GLFWAPI GLFWtheme* glfwCreateTheme(void);
+GLFWAPI void glfwDestroyTheme(GLFWtheme* theme);
+GLFWAPI void glfwCopyTheme(const GLFWtheme* source, GLFWtheme* target);
+
+GLFWAPI int glfwThemeGetVariation(const GLFWtheme* theme);
+GLFWAPI void glfwThemeSetVariation(GLFWtheme* theme, int value);
+
+GLFWAPI int glfwThemeGetFlags(const GLFWtheme* theme);
+GLFWAPI void glfwThemeSetFlags(GLFWtheme* theme, int value);
+
+GLFWAPI void glfwThemeGetColor(const GLFWtheme* theme, float* red, float* green, float* blue, float* alpha);
+GLFWAPI void glfwThemeSetColor(GLFWtheme* theme, float red, float green, float blue, float alpha);
+
+#define GLFW_THEME_DARK -1
+#define GLFW_THEME_DEFAULT 0
+#define GLFW_THEME_LIGHT 1
 
 #define GLFW_THEME_FLAG_HAS_COLOR 1
 #define GLFW_THEME_FLAG_HIGH_CONTRAST 2
@@ -5872,7 +5887,7 @@ GLFWAPI GLFWthemefun glfwSetSystemThemeCallback(GLFWthemefun callback);
  *  @param[in] window The window to set the theme for.
  *  @param[in] theme The theme to set. Pass `NULL` to set it to the system default.
  */
-GLFWAPI void glfwSetTheme(GLFWwindow* handle, GLFWtheme* theme);
+GLFWAPI void glfwSetTheme(GLFWwindow* handle, const GLFWtheme* theme);
 GLFWAPI GLFWtheme* glfwGetTheme(GLFWwindow* handle);
 GLFWAPI GLFWtheme* glfwGetSystemDefaultTheme();
 
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 01f191c9..09427835 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -3,7 +3,7 @@ add_library(glfw ${GLFW_LIBRARY_TYPE}
                  "${GLFW_SOURCE_DIR}/include/GLFW/glfw3.h"
                  "${GLFW_SOURCE_DIR}/include/GLFW/glfw3native.h"
                  internal.h platform.h mappings.h
-                 context.c init.c input.c monitor.c platform.c vulkan.c window.c
+                 context.c init.c input.c monitor.c platform.c theme.c vulkan.c window.c
                  egl_context.c osmesa_context.c null_platform.h null_joystick.h
                  null_init.c null_monitor.c null_window.c null_joystick.c)
 
@@ -248,7 +248,7 @@ endif()
 # Make GCC warn about declarations that VS 2010 and 2012 won't accept for all
 # source files that VS will build (Clang ignores this because we set -std=c99)
 if (CMAKE_C_COMPILER_ID STREQUAL "GNU")
-    set_source_files_properties(context.c init.c input.c monitor.c platform.c vulkan.c
+    set_source_files_properties(context.c init.c input.c monitor.c platform.c theme.c vulkan.c
                                 window.c null_init.c null_joystick.c null_monitor.c
                                 null_window.c win32_init.c win32_joystick.c win32_module.c
                                 win32_monitor.c win32_time.c win32_thread.c win32_window.c
diff --git a/src/cocoa_init.m b/src/cocoa_init.m
index 9570d4c2..5c8b0e82 100644
--- a/src/cocoa_init.m
+++ b/src/cocoa_init.m
@@ -175,7 +175,7 @@ static void createMenuBar(void)
     [NSApp performSelector:setAppleMenuSelector withObject:appMenu];
 }
 
-void nsAppearanceToGLFWTheme(NSAppearance* appearance, GLFWtheme* theme)
+void nsAppearanceToGLFWTheme(NSAppearance* appearance, _GLFWtheme* theme)
 {
     NSAppearanceName name;
     
@@ -197,20 +197,20 @@ void nsAppearanceToGLFWTheme(NSAppearance* appearance, GLFWtheme* theme)
     
     if ([name isEqualToString:NSAppearanceNameAqua])
     {
-        theme->baseTheme = GLFW_BASE_THEME_LIGHT;
+        theme->variation = GLFW_THEME_LIGHT;
         return;
     }
     
     if (@available(macOS 10.10, *)) {
         if ([name isEqualToString:NSAppearanceNameVibrantLight])
         {
-            theme->baseTheme = GLFW_BASE_THEME_LIGHT;
+            theme->variation = GLFW_THEME_LIGHT;
             theme->flags |= GLFW_THEME_FLAG_VIBRANT;
             return;
         }
         if ([name isEqualToString:NSAppearanceNameVibrantDark])
         {
-            theme->baseTheme = GLFW_BASE_THEME_DARK;
+            theme->variation = GLFW_THEME_DARK;
             theme->flags |= GLFW_THEME_FLAG_VIBRANT;
             return;
         }
@@ -220,36 +220,36 @@ void nsAppearanceToGLFWTheme(NSAppearance* appearance, GLFWtheme* theme)
     {
         if ([name isEqualToString:NSAppearanceNameDarkAqua])
         {
-            theme->baseTheme = GLFW_BASE_THEME_DARK;
+            theme->variation = GLFW_THEME_DARK;
             return;
         }
         if ([name isEqualToString:NSAppearanceNameAccessibilityHighContrastAqua])
         {
-            theme->baseTheme = GLFW_BASE_THEME_LIGHT;
+            theme->variation = GLFW_THEME_LIGHT;
             theme->flags |= GLFW_THEME_FLAG_HIGH_CONTRAST;
             return;
         }
         if ([name isEqualToString:NSAppearanceNameAccessibilityHighContrastDarkAqua])
         {
-            theme->baseTheme = GLFW_BASE_THEME_DARK;
+            theme->variation = GLFW_THEME_DARK;
             theme->flags |= GLFW_THEME_FLAG_HIGH_CONTRAST;
             return;
         }
         if ([name isEqualToString:NSAppearanceNameAccessibilityHighContrastVibrantLight])
         {
-            theme->baseTheme = GLFW_BASE_THEME_LIGHT;
+            theme->variation = GLFW_THEME_LIGHT;
             theme->flags |= GLFW_THEME_FLAG_VIBRANT | GLFW_THEME_FLAG_HIGH_CONTRAST;
             return;
         }
         if ([name isEqualToString:NSAppearanceNameAccessibilityHighContrastVibrantDark])
         {
-            theme->baseTheme = GLFW_BASE_THEME_DARK;
+            theme->variation = GLFW_THEME_DARK;
             theme->flags |= GLFW_THEME_FLAG_VIBRANT | GLFW_THEME_FLAG_HIGH_CONTRAST;
             return;
         }
     }
     
-    theme->baseTheme = GLFW_BASE_THEME_LIGHT;
+    theme->variation = GLFW_THEME_LIGHT;
 }
 
 // Create key code translation tables
@@ -491,9 +491,12 @@ static GLFWbool initializeTIS(void)
     
     // TODO: FIXME: this method is invoked twice when the high contrast setting is edited in the preferences.
     
-    GLFWtheme theme = { GLFW_BASE_THEME_LIGHT, 0 };
+    _GLFWtheme theme = { GLFW_THEME_LIGHT, 0 };
     
     if (@available(macOS 10.14, *)) {
+        // effectiveAppearance is actually not the system appearance, but the application appearance.
+        // As long as NSApplication.appearance is never set, using the effective appearance is fine
+        // to get and observe the system appearance.
         nsAppearanceToGLFWTheme(NSApp.effectiveAppearance, &theme);
         
         NSColor* color = [[NSColor controlAccentColor] colorUsingColorSpace:NSColorSpace.genericRGBColorSpace];
@@ -842,7 +845,7 @@ void _glfwTerminateCocoa(void)
     } // autoreleasepool
 }
 
-GLFWtheme* _glfwGetSystemDefaultThemeCocoa(void)
+_GLFWtheme* _glfwGetSystemDefaultThemeCocoa(void)
 {
     _glfwInputError(GLFW_FEATURE_UNIMPLEMENTED, NULL);
     return NULL; // TODO: implement
diff --git a/src/cocoa_platform.h b/src/cocoa_platform.h
index 84a0ace0..6e6f9054 100644
--- a/src/cocoa_platform.h
+++ b/src/cocoa_platform.h
@@ -297,7 +297,7 @@ void _glfwRestoreVideoModeCocoa(_GLFWmonitor* monitor);
 
 float _glfwTransformYCocoa(float y);
 
-void nsAppearanceToGLFWTheme(NSAppearance* appearance, GLFWtheme* theme);
+void nsAppearanceToGLFWTheme(NSAppearance* appearance, _GLFWtheme* theme);
 
 void* _glfwLoadLocalVulkanLoaderCocoa(void);
 
@@ -309,6 +309,6 @@ GLFWbool _glfwCreateContextNSGL(_GLFWwindow* window,
 void _glfwDestroyContextNSGL(_GLFWwindow* window);
 
 
-GLFWtheme* _glfwGetSystemDefaultThemeCocoa(void);
-void _glfwSetThemeCocoa(_GLFWwindow* window, GLFWtheme* theme);
-GLFWtheme* _glfwGetThemeCocoa(_GLFWwindow* window);
+_GLFWtheme* _glfwGetSystemDefaultThemeCocoa(void);
+void _glfwSetThemeCocoa(_GLFWwindow* window, _GLFWtheme* theme);
+_GLFWtheme* _glfwGetThemeCocoa(_GLFWwindow* window);
diff --git a/src/cocoa_window.m b/src/cocoa_window.m
index 6ba54501..b99a9e85 100644
--- a/src/cocoa_window.m
+++ b/src/cocoa_window.m
@@ -1876,9 +1876,9 @@ const char* _glfwGetClipboardStringCocoa(void)
     } // autoreleasepool
 }
 
-void _glfwSetThemeCocoa(_GLFWwindow* window, GLFWtheme* theme)
+void _glfwSetThemeCocoa(_GLFWwindow* window, _GLFWtheme* theme)
 {
-    if (!theme || theme->baseTheme == GLFW_BASE_THEME_DEFAULT)
+    if (!theme || theme->variation == GLFW_THEME_DEFAULT)
     {
         [(NSWindow*)window->ns.object setAppearance:nil];
         return;
@@ -1896,7 +1896,7 @@ void _glfwSetThemeCocoa(_GLFWwindow* window, GLFWtheme* theme)
     // appearanceNamed: will result in nil, so these can not be used.
     NSAppearanceName name;
     
-    if (theme->baseTheme == GLFW_BASE_THEME_LIGHT)
+    if (theme->variation == GLFW_THEME_LIGHT)
     {
         if (theme->flags & GLFW_THEME_FLAG_VIBRANT)
         {
@@ -1926,11 +1926,11 @@ void _glfwSetThemeCocoa(_GLFWwindow* window, GLFWtheme* theme)
     [(NSWindow*)window->ns.object setAppearance:appearance];
 }
 
-GLFWtheme* _glfwGetThemeCocoa(_GLFWwindow* window)
+_GLFWtheme* _glfwGetThemeCocoa(_GLFWwindow* window)
 {
-    GLFWtheme* theme = &window->theme;
+    _GLFWtheme* theme = &window->theme;
     
-    theme->baseTheme = GLFW_BASE_THEME_LIGHT;
+    theme->variation = GLFW_THEME_LIGHT;
     theme->flags = 0;
     
     if (@available(macOS 10.09, *))
diff --git a/src/init.c b/src/init.c
index 41107ee8..69d391c1 100644
--- a/src/init.c
+++ b/src/init.c
@@ -546,7 +546,11 @@ GLFWAPI GLFWerrorfun glfwSetErrorCallback(GLFWerrorfun cbfun)
 GLFWAPI GLFWtheme* glfwGetSystemDefaultTheme()
 {
     _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
-    return _glfw.platform.getSystemDefaultTheme();
+    
+    _GLFWtheme* theme = _glfw.platform.getSystemDefaultTheme();
+    assert(theme->variation != GLFW_THEME_DEFAULT); 
+    
+    return (GLFWtheme*) theme;
 }
 
 GLFWAPI GLFWthemefun glfwSetSystemThemeCallback(GLFWthemefun callback)
diff --git a/src/input.c b/src/input.c
index dc2ab137..03fc41cb 100644
--- a/src/input.c
+++ b/src/input.c
@@ -477,12 +477,12 @@ void _glfwInputJoystickHat(_GLFWjoystick* js, int hat, char value)
     js->hats[hat] = value;
 }
 
-void _glfwInputSystemTheme(GLFWtheme* theme)
+void _glfwInputSystemTheme(_GLFWtheme* theme)
 {
     assert(theme != NULL);
     
     if (_glfw.callbacks.theme)
-        _glfw.callbacks.theme(theme);
+        _glfw.callbacks.theme((GLFWtheme*) theme);
 }
 
 //////////////////////////////////////////////////////////////////////////
diff --git a/src/internal.h b/src/internal.h
index 5d3ec9a6..9795fc6b 100644
--- a/src/internal.h
+++ b/src/internal.h
@@ -571,7 +571,7 @@ struct _GLFWwindow
         GLFWdropfun               drop;
     } callbacks;
     
-    GLFWtheme theme;
+    _GLFWtheme theme; // TODO: This data is mutable by clients, so remove it.
 
     // This is defined in platform.h
     GLFW_PLATFORM_WINDOW_STATE
@@ -675,7 +675,7 @@ struct _GLFWplatform
     // Init
     GLFWbool (*init)(void);
     void (*terminate)(void);
-    GLFWtheme* (*getSystemDefaultTheme)(void);
+    _GLFWtheme* (*getSystemDefaultTheme)(void);
     // Input
     void (*getCursorPos)(_GLFWwindow*,double*,double*);
     void (*setCursorPos)(_GLFWwindow*,double,double);
@@ -738,8 +738,8 @@ struct _GLFWplatform
     void (*setWindowFloating)(_GLFWwindow*,GLFWbool);
     void (*setWindowOpacity)(_GLFWwindow*,float);
     void (*setWindowMousePassthrough)(_GLFWwindow*,GLFWbool);
-    GLFWtheme* (*getTheme)(_GLFWwindow*);
-    void (*setTheme)(_GLFWwindow*,GLFWtheme*);
+    _GLFWtheme* (*getTheme)(_GLFWwindow*);
+    void (*setTheme)(_GLFWwindow*,_GLFWtheme*);
     // Events
     void (*pollEvents)(void);
     void (*waitEvents)(void);
@@ -936,7 +936,7 @@ void _glfwInputJoystickAxis(_GLFWjoystick* js, int axis, float value);
 void _glfwInputJoystickButton(_GLFWjoystick* js, int button, char value);
 void _glfwInputJoystickHat(_GLFWjoystick* js, int hat, char value);
 
-void _glfwInputSystemTheme(GLFWtheme* theme);
+void _glfwInputSystemTheme(_GLFWtheme* theme);
 
 void _glfwInputMonitor(_GLFWmonitor* monitor, int action, int placement);
 void _glfwInputMonitorWindow(_GLFWmonitor* monitor, _GLFWwindow* window);
diff --git a/src/null_init.c b/src/null_init.c
index f42f70b4..15738873 100644
--- a/src/null_init.c
+++ b/src/null_init.c
@@ -140,7 +140,7 @@ void _glfwTerminateNull(void)
     _glfwTerminateEGL();
 }
 
-GLFWtheme* _glfwGetSystemDefaultThemeNull(void)
+_GLFWtheme* _glfwGetSystemDefaultThemeNull(void)
 {
-    return NULL; // TODO: should probably return a colorless GLFWtheme with baseTheme set to GLFW_BASE_THEME_LIGHT
+    return NULL; // TODO: should probably return a colorless GLFWtheme with baseTheme set to GLFW_THEME_LIGHT
 }
diff --git a/src/null_platform.h b/src/null_platform.h
index 44a61cad..b5abe2b0 100644
--- a/src/null_platform.h
+++ b/src/null_platform.h
@@ -147,6 +147,6 @@ VkResult _glfwCreateWindowSurfaceNull(VkInstance instance, _GLFWwindow* window,
 
 void _glfwPollMonitorsNull(void);
 
-GLFWtheme* _glfwGetSystemDefaultThemeNull(void);
-void _glfwSetThemeNull(_GLFWwindow* window, GLFWtheme* theme);
-GLFWtheme* _glfwGetThemeNull(_GLFWwindow* window);
+_GLFWtheme* _glfwGetSystemDefaultThemeNull(void);
+void _glfwSetThemeNull(_GLFWwindow* window, _GLFWtheme* theme);
+_GLFWtheme* _glfwGetThemeNull(_GLFWwindow* window);
diff --git a/src/null_window.c b/src/null_window.c
index 2804fa59..c0d3264a 100644
--- a/src/null_window.c
+++ b/src/null_window.c
@@ -551,11 +551,11 @@ const char* _glfwGetClipboardStringNull(void)
     return _glfw.null.clipboardString;
 }
 
-void _glfwSetThemeNull(_GLFWwindow* window, GLFWtheme* theme)
+void _glfwSetThemeNull(_GLFWwindow* window, _GLFWtheme* theme)
 {
 }
 
-GLFWtheme* _glfwGetThemeNull(_GLFWwindow* window)
+_GLFWtheme* _glfwGetThemeNull(_GLFWwindow* window)
 {
     return NULL; // TODO: see to-do in _glfwGetSystemDefaultThemeNull
 }
diff --git a/src/theme.c b/src/theme.c
new file mode 100644
index 00000000..bcb119a0
--- /dev/null
+++ b/src/theme.c
@@ -0,0 +1,88 @@
+//
+//  theme.c
+//  glfw
+//
+//  Created by Andreas Ormevik Jansen on 28/01/2023.
+//
+
+#include "internal.h"
+
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include <assert.h>
+
+
+GLFWAPI GLFWtheme* glfwCreateTheme(void)
+{
+    _GLFWtheme* theme = _glfw_calloc(1, sizeof(_GLFWtheme));
+    
+    theme->variation = GLFW_THEME_DEFAULT;
+    theme->flags = 0;
+    
+    return (GLFWtheme*) theme;
+}
+
+GLFWAPI void glfwDestroyTheme(GLFWtheme* theme)
+{
+    _glfw_free((_GLFWtheme*) theme);
+}
+
+GLFWAPI void glfwCopyTheme(const GLFWtheme* source, GLFWtheme* target)
+{
+    memcpy(target, source, sizeof(_GLFWtheme));
+}
+
+GLFWAPI int glfwThemeGetVariation(const GLFWtheme* theme)
+{
+    assert(theme != NULL);
+    return ((_GLFWtheme*) theme)->variation;
+}
+
+GLFWAPI void glfwThemeSetVariation(GLFWtheme* theme, int value)
+{
+    assert(theme != NULL);
+    assert(value == GLFW_THEME_DARK || value == GLFW_THEME_DEFAULT || value == GLFW_THEME_LIGHT);
+    
+    ((_GLFWtheme*) theme)->variation = value;
+}
+
+GLFWAPI int glfwThemeGetFlags(const GLFWtheme* theme)
+{
+    assert(theme != NULL);
+    return ((_GLFWtheme*) theme)->flags;
+}
+
+GLFWAPI void glfwThemeSetFlags(GLFWtheme* theme, int value)
+{
+    assert(theme != NULL);
+    assert((value & ~(GLFW_THEME_FLAG_HAS_COLOR | GLFW_THEME_FLAG_HIGH_CONTRAST | GLFW_THEME_FLAG_VIBRANT)) == 0);
+    
+    ((_GLFWtheme*) theme)->flags = value;
+}
+
+GLFWAPI void glfwThemeGetColor(const GLFWtheme* theme, float* red, float* green, float* blue, float* alpha)
+{
+    assert(theme != NULL);
+    assert(red != NULL && green != NULL && blue != NULL && alpha != NULL);
+    
+    const _GLFWtheme* iTheme = ((_GLFWtheme*) theme);
+    
+    *red   = iTheme->color[0] / 255.0f;
+    *green = iTheme->color[1] / 255.0f;
+    *blue  = iTheme->color[2] / 255.0f;
+    *alpha = iTheme->color[3] / 255.0f;
+}
+
+GLFWAPI void glfwThemeSetColor(GLFWtheme* theme, float red, float green, float blue, float alpha)
+{
+    assert(theme != NULL);
+    
+    _GLFWtheme* iTheme = ((_GLFWtheme*) theme);
+    
+    iTheme->color[0] = red * 255.0f;
+    iTheme->color[1] = green * 255.0f;
+    iTheme->color[2] = blue * 255.0f;
+    iTheme->color[3] = alpha * 255.0f;
+}
diff --git a/src/win32_init.c b/src/win32_init.c
index 2ee73b23..3bba1f65 100644
--- a/src/win32_init.c
+++ b/src/win32_init.c
@@ -737,7 +737,7 @@ void _glfwTerminateWin32(void)
     freeLibraries();
 }
 
-GLFWtheme* _glfwGetSystemDefaultThemeWin32(void)
+_GLFWtheme* _glfwGetSystemDefaultThemeWin32(void)
 {
     _glfwInputError(GLFW_FEATURE_UNIMPLEMENTED, NULL);
     return NULL; // TODO: implement
diff --git a/src/win32_platform.h b/src/win32_platform.h
index ca46cb16..fd7624f0 100644
--- a/src/win32_platform.h
+++ b/src/win32_platform.h
@@ -622,6 +622,6 @@ GLFWbool _glfwCreateContextWGL(_GLFWwindow* window,
                                const _GLFWctxconfig* ctxconfig,
                                const _GLFWfbconfig* fbconfig);
 
-GLFWtheme* _glfwGetSystemDefaultThemeWin32(void);
-void _glfwSetThemeWin32(_GLFWwindow* window, GLFWtheme* theme);
-GLFWtheme* _glfwGetThemeWin32(_GLFWwindow* window);
+_GLFWtheme* _glfwGetSystemDefaultThemeWin32(void);
+void _glfwSetThemeWin32(_GLFWwindow* window, _GLFWtheme* theme);
+_GLFWtheme* _glfwGetThemeWin32(_GLFWwindow* window);
diff --git a/src/win32_window.c b/src/win32_window.c
index 53a11a14..0a73f36b 100644
--- a/src/win32_window.c
+++ b/src/win32_window.c
@@ -2373,12 +2373,12 @@ const char* _glfwGetClipboardStringWin32(void)
     return _glfw.win32.clipboardString;
 }
 
-void _glfwSetThemeWin32(_GLFWwindow* window, GLFWtheme* theme)
+void _glfwSetThemeWin32(_GLFWwindow* window, _GLFWtheme* theme)
 {
     _glfwInputError(GLFW_FEATURE_UNIMPLEMENTED, NULL);
 }
 
-GLFWtheme* _glfwGetThemeWin32(_GLFWwindow* window)
+_GLFWtheme* _glfwGetThemeWin32(_GLFWwindow* window)
 {
     _glfwInputError(GLFW_FEATURE_UNIMPLEMENTED, NULL);
     return NULL; // TODO: implement
diff --git a/src/window.c b/src/window.c
index e380d3fb..12bd4a30 100644
--- a/src/window.c
+++ b/src/window.c
@@ -1160,7 +1160,7 @@ GLFWAPI void glfwSetTheme(GLFWwindow* handle, GLFWtheme* theme)
     assert(window != NULL);
     
     _GLFW_REQUIRE_INIT();
-    _glfw.platform.setTheme(window, theme);
+    _glfw.platform.setTheme(window, (_GLFWtheme*) theme);
 }
 
 GLFWAPI GLFWtheme* glfwGetTheme(GLFWwindow* handle)
@@ -1169,5 +1169,5 @@ GLFWAPI GLFWtheme* glfwGetTheme(GLFWwindow* handle)
     assert(window != NULL);
     
     _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
-    return _glfw.platform.getTheme(window);
+    return (GLFWtheme*) _glfw.platform.getTheme(window);
 }
diff --git a/src/wl_init.c b/src/wl_init.c
index b28e0e15..0efa0007 100644
--- a/src/wl_init.c
+++ b/src/wl_init.c
@@ -803,7 +803,7 @@ void _glfwTerminateWayland(void)
     _glfw_free(_glfw.wl.clipboardString);
 }
 
-GLFWtheme* _glfwGetSystemDefaultThemeWayland(void)
+_GLFWtheme* _glfwGetSystemDefaultThemeWayland(void)
 {
     _glfwInputError(GLFW_FEATURE_UNIMPLEMENTED, NULL);
     return NULL; // TODO: implement
diff --git a/src/wl_platform.h b/src/wl_platform.h
index af357cac..bf19f16a 100644
--- a/src/wl_platform.h
+++ b/src/wl_platform.h
@@ -519,6 +519,6 @@ void _glfwUpdateContentScaleWayland(_GLFWwindow* window);
 void _glfwAddSeatListenerWayland(struct wl_seat* seat);
 void _glfwAddDataDeviceListenerWayland(struct wl_data_device* device);
 
-GLFWtheme* _glfwGetSystemDefaultThemeWayland(void);
-void _glfwSetThemeWayland(_GLFWwindow* window, GLFWtheme* theme);
-GLFWtheme* _glfwGetThemeWayland(_GLFWwindow* window);
+_GLFWtheme* _glfwGetSystemDefaultThemeWayland(void);
+void _glfwSetThemeWayland(_GLFWwindow* window, _GLFWtheme* theme);
+_GLFWtheme* _glfwGetThemeWayland(_GLFWwindow* window);
diff --git a/src/wl_window.c b/src/wl_window.c
index 48a60b52..ed490155 100644
--- a/src/wl_window.c
+++ b/src/wl_window.c
@@ -2775,12 +2775,12 @@ const char* _glfwGetClipboardStringWayland(void)
     return _glfw.wl.clipboardString;
 }
 
-void _glfwSetThemeWayland(_GLFWwindow* window, GLFWtheme* theme)
+void _glfwSetThemeWayland(_GLFWwindow* window, _GLFWtheme* theme)
 {
     _glfwInputError(GLFW_FEATURE_UNIMPLEMENTED, NULL);
 }
 
-GLFWtheme* _glfwGetThemeWayland(_GLFWwindow* window)
+_GLFWtheme* _glfwGetThemeWayland(_GLFWwindow* window)
 {
     _glfwInputError(GLFW_FEATURE_UNIMPLEMENTED, NULL);
     return NULL; // TODO: implement
diff --git a/src/x11_init.c b/src/x11_init.c
index 21645b94..582624b9 100644
--- a/src/x11_init.c
+++ b/src/x11_init.c
@@ -1664,7 +1664,7 @@ void _glfwTerminateX11(void)
     }
 }
 
-GLFWtheme* _glfwGetSystemDefaultThemeX11(void)
+_GLFWtheme* _glfwGetSystemDefaultThemeX11(void)
 {
     _glfwInputError(GLFW_FEATURE_UNIMPLEMENTED, NULL);
     return NULL; // TODO: implement
diff --git a/src/x11_platform.h b/src/x11_platform.h
index e0214699..5cff4c7a 100644
--- a/src/x11_platform.h
+++ b/src/x11_platform.h
@@ -1002,6 +1002,6 @@ GLFWbool _glfwChooseVisualGLX(const _GLFWwndconfig* wndconfig,
                               const _GLFWfbconfig* fbconfig,
                               Visual** visual, int* depth);
 
-GLFWtheme* _glfwGetSystemDefaultThemeX11(void);
-void _glfwSetThemeX11(_GLFWwindow* window, GLFWtheme* theme);
-GLFWtheme* _glfwGetThemeX11(_GLFWwindow* window);
+_GLFWtheme* _glfwGetSystemDefaultThemeX11(void);
+void _glfwSetThemeX11(_GLFWwindow* window, _GLFWtheme* theme);
+_GLFWtheme* _glfwGetThemeX11(_GLFWwindow* window);
diff --git a/src/x11_window.c b/src/x11_window.c
index f3adc490..675f5014 100644
--- a/src/x11_window.c
+++ b/src/x11_window.c
@@ -3082,12 +3082,12 @@ const char* _glfwGetClipboardStringX11(void)
     return getSelectionString(_glfw.x11.CLIPBOARD);
 }
 
-void _glfwSetThemeX11(_GLFWwindow* window, GLFWtheme* theme)
+void _glfwSetThemeX11(_GLFWwindow* window, _GLFWtheme* theme)
 {
     _glfwInputError(GLFW_FEATURE_UNIMPLEMENTED, NULL);
 }
 
-GLFWtheme* _glfwGetThemeX11(_GLFWwindow* window)
+_GLFWtheme* _glfwGetThemeX11(_GLFWwindow* window)
 {
     _glfwInputError(GLFW_FEATURE_UNIMPLEMENTED, NULL);
     return NULL; // TODO: implement
diff --git a/tests/theming.c b/tests/theming.c
index c74425c8..21bab47b 100644
--- a/tests/theming.c
+++ b/tests/theming.c
@@ -36,75 +36,84 @@
 #include <stdlib.h>
 #include <string.h>
 
-const unsigned char theme_colors[6][4] =
+const float theme_colors[6][4] =
 {
-    {   0,   0,   0, 255 }, // black
-    { 255,   0,   0, 255 }, // red
-    {   0, 255,   0, 255 }, // green
-    {   0,   0, 255, 255 }, // blue
-    { 255, 255, 255, 255 }, // white
-    { 128, 128, 128, 255 }  // gray (no theme color)
+    {   0,   0,   0, 1.0 }, // black
+    { 1.0,   0,   0, 1.0 }, // red
+    {   0, 1.0,   0, 1.0 }, // green
+    {   0,   0, 1.0, 1.0 }, // blue
+    { 1.0, 1.0, 1.0, 1.0 }, // white
+    { 0.5, 0.5, 0.5, 1.0 }  // gray (no theme color)
 };
 
 static int cur_theme_color = 0;
 
-static GLFWtheme theme;
+static GLFWtheme* theme;
 
 static void print_theme(GLFWtheme* theme, const char* title)
 {
+    const int flags = glfwThemeGetFlags(theme);
     int n = 0;
     
     printf("%s: {\n", title);
-    printf("    Base: %s\n", theme->baseTheme == GLFW_BASE_THEME_LIGHT ? "light" : "dark");
+    printf("    Base: %s\n", glfwThemeGetVariation(theme) == GLFW_THEME_LIGHT ? "light" : "dark");
     printf("    Flags: [");
-    if (theme->flags & GLFW_THEME_FLAG_HAS_COLOR)
+    if (flags & GLFW_THEME_FLAG_HAS_COLOR)
     {
         printf(n++ > 0 ? ", %s" : "%s", "HAS_COLOR");
     }
-    if (theme->flags & GLFW_THEME_FLAG_VIBRANT)
+    if (flags & GLFW_THEME_FLAG_VIBRANT)
     {
         printf(n++ > 0 ? ", %s" : "%s", "VIBRANT");
     }
-    if (theme->flags & GLFW_THEME_FLAG_HIGH_CONTRAST)
+    if (flags & GLFW_THEME_FLAG_HIGH_CONTRAST)
     {
         printf(n++ > 0 ? ", %s" : "%s", "HIGH_CONTRAST");
     }
     printf("]\n");
-    if (theme->flags & GLFW_THEME_FLAG_HAS_COLOR)
+    if (flags & GLFW_THEME_FLAG_HAS_COLOR)
     {
-        printf("    Color: [%i, %i, %i, %i]\n", theme->color[0], theme->color[1], theme->color[2], theme->color[3]);
+        float r, g, b, a;
+        glfwThemeGetColor(theme, &r, &g, &b, &a);
+        printf("    Color: [%f, %f, %f, %f]\n", r, g, b, a);
     }
     printf("}\n");
 }
 
 static void set_theme(GLFWwindow* window, int theme_color)
 {
-    memcpy(theme.color, theme_colors[theme_color], 4);
+    glfwThemeSetColor(
+            theme,
+            theme_colors[theme_color][0],
+            theme_colors[theme_color][1],
+            theme_colors[theme_color][2],
+            theme_colors[theme_color][3]
+    );
     
     if (theme_color == 6)
     {
-        theme.flags &= ~GLFW_THEME_FLAG_HAS_COLOR;
+        glfwThemeSetFlags(theme, glfwThemeGetFlags(theme) & ~GLFW_THEME_FLAG_HAS_COLOR);
     } else
     {
-        theme.flags |= GLFW_THEME_FLAG_HAS_COLOR;
+        glfwThemeSetFlags(theme, glfwThemeGetFlags(theme) | GLFW_THEME_FLAG_HAS_COLOR);
     }
 
     const char* title;
     
-    switch (theme.baseTheme) {
-        case GLFW_BASE_THEME_DEFAULT:
+    switch (glfwThemeGetVariation(theme)) {
+        case GLFW_THEME_DEFAULT:
             title = "Default theme";
             break;
-        case GLFW_BASE_THEME_LIGHT:
+        case GLFW_THEME_LIGHT:
             title = "Light theme";
             break;
-        case GLFW_BASE_THEME_DARK:
+        case GLFW_THEME_DARK:
             title = "Dark theme";
             break;
     }
     
     glfwSetWindowTitle(window, title);
-    glfwSetTheme(window, &theme);
+    glfwSetTheme(window, theme);
 }
 
 static void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
@@ -119,15 +128,15 @@ static void key_callback(GLFWwindow* window, int key, int scancode, int action,
             glfwSetTheme(window, NULL);
             break;
         case GLFW_KEY_1:
-            theme.baseTheme = GLFW_BASE_THEME_DEFAULT;
+            glfwThemeSetVariation(theme, GLFW_THEME_DEFAULT);
             set_theme(window, cur_theme_color);
             break;
         case GLFW_KEY_2:
-            theme.baseTheme = GLFW_BASE_THEME_LIGHT;
+            glfwThemeSetVariation(theme, GLFW_THEME_LIGHT);
             set_theme(window, cur_theme_color);
             break;
         case GLFW_KEY_3:
-            theme.baseTheme = GLFW_BASE_THEME_DARK;
+            glfwThemeSetVariation(theme, GLFW_THEME_DARK);
             set_theme(window, cur_theme_color);
             break;
         case GLFW_KEY_ESCAPE:
@@ -172,12 +181,11 @@ int main(int argc, char** argv)
 
     glfwSetKeyCallback(window, key_callback);
     
-    theme.baseTheme = GLFW_BASE_THEME_DEFAULT;
-    theme.flags = 0;
-    theme.color[0] = 0;
-    theme.color[1] = 0;
-    theme.color[2] = 0;
-    theme.color[3] = 0;
+    theme = glfwCreateTheme();
+    
+    glfwThemeSetVariation(theme, GLFW_THEME_DEFAULT);
+    glfwThemeSetFlags(theme, 0);
+    glfwThemeSetColor(theme, 0, 0, 0, 0);
     set_theme(window, cur_theme_color);
     
     glfwSetSystemThemeCallback(theme_callback);
@@ -195,6 +203,7 @@ int main(int argc, char** argv)
         glfwWaitEvents();
     }
 
+    glfwDestroyTheme(theme);
     glfwDestroyWindow(window);
     glfwTerminate();
     exit(EXIT_SUCCESS);