How to create native dark menu's using the Win32 API

DarkMode.h

// DarkMode.h
#pragma once

/**
 * @brief Windows Dark Mode Menu Controller
 * 
 * Provides functionality to force dark mode on Windows menus using the UxTheme API.
 * This implementation uses undocumented Windows functions to achieve consistent
 * dark mode appearance across the application's menus.
 * 
 * @author Aman Yadav
 * @date February 2025
 */

#ifndef DARK_MODE_H
#define DARK_MODE_H

#include <Windows.h>

namespace DarkMode {
    /**
     * @brief Application theme modes
     */
    enum class PreferredAppMode {
        Default,     ///< System default theme
        AllowDark,   ///< Allow dark mode if system uses it
        ForceDark,   ///< Always use dark mode
        ForceLight,  ///< Always use light mode
        Max         ///< Enum boundary
    };

    /**
     * @brief Initialize dark mode for application menus
     * @return true if dark mode was successfully initialized
     */
    bool InitializeDarkMode();
}

#endif // DARK_MODE_H

// DarkMode.cpp
#include "DarkMode.h"
#include <Uxtheme.h>

namespace {
    using fnSetPreferredAppMode = DarkMode::PreferredAppMode(WINAPI*)(DarkMode::PreferredAppMode appMode);
    using fnFlushMenuThemes = void(WINAPI*)();

    fnSetPreferredAppMode pfnSetPreferredAppMode = nullptr;
    fnFlushMenuThemes pfnFlushMenuThemes = nullptr;
}

namespace DarkMode {
    bool InitializeDarkMode() {
        HMODULE hUxTheme = LoadLibraryEx(L"uxtheme.dll", nullptr, LOAD_LIBRARY_SEARCH_SYSTEM32);
        if (!hUxTheme) {
            return false;
        }

        pfnFlushMenuThemes = reinterpret_cast<fnFlushMenuThemes>(
            GetProcAddress(hUxTheme, MAKEINTRESOURCEA(136)));
        pfnSetPreferredAppMode = reinterpret_cast<fnSetPreferredAppMode>(
            GetProcAddress(hUxTheme, MAKEINTRESOURCEA(135)));

        if (!pfnFlushMenuThemes || !pfnSetPreferredAppMode) {
            FreeLibrary(hUxTheme);
            return false;
        }

        pfnSetPreferredAppMode(PreferredAppMode::ForceDark);
        pfnFlushMenuThemes();

        return true;
    }
}