Get information about current Windows theme in C#

ThemeInfo.cs

public class ThemeInfo
{
    private readonly string _themeName;
    private readonly string _themeColor;
    private readonly string _themeSize;
    private readonly string _themeFileName;

    public ThemeInfo(string name, string fileName, string color, string size)
    {
        _themeName = name;
        _themeFileName = fileName;
        _themeColor = color;
        _themeSize = size;
    }

    public string ThemeFileName
    {
        get { return _themeFileName; }
    }

    public string ThemeName
    {
        get { return _themeName; }
    }

    public string ThemeColor
    {
        get { return _themeColor; }
    }

    public string ThemeSize
    {
        get { return _themeSize; }
    }
    
    public static ThemeInfo Current
    {
        get
        {
            var fileName = new StringBuilder(260);
            var color = new StringBuilder(260);
            var size = new StringBuilder(260);
            int hresult = GetCurrentThemeName(fileName, fileName.Capacity, color, color.Capacity, size, size.Capacity);
            if (hresult < 0)
                throw Marshal.GetExceptionForHR(hresult);
            string themeName = Path.GetFileNameWithoutExtension(fileName.ToString());
            return new ThemeInfo(themeName, fileName.ToString(), color.ToString(), size.ToString());
        }
    }
    
    [DllImport("uxtheme", CharSet = CharSet.Auto)]
    private static extern int GetCurrentThemeName(
    StringBuilder pszThemeFileName,
    int dwMaxNameChars,
    StringBuilder pszColorBuff,
    int cchMaxColorChars,
    StringBuilder pszSizeBuff,
    int cchMaxSizeChars
    );
}

ThemeColor is "NormalColor" .. what would you do with that? It's useless

ThemeColor is "NormalColor" .. what would you do with that? It's useless

• Option 1: Registry (accurate)
  • Good if you want the actual color that is selected in your personalization settings

public static (byte A, byte R, byte G, byte B)? GetDWMAccent() {
    try {
        const string registryKeyPath = @"Software\Microsoft\Windows\DWM";
        const string valueName = "AccentColor";
        using RegistryKey? key = Registry.CurrentUser.OpenSubKey(registryKeyPath);
        if (key is null) return null;
        object? color = key.GetValue(valueName);
        if (color is null) return null;

        // It is ABGR not ARGB because windows sucks
        // Map int to uint while preserving the value relative to the type
        uint abgr = unchecked((uint)(int)color);
        // split abgr (uint) into a,b,g,r (bytes)
        byte a = (byte)((abgr & 0xFF000000) >> 24);
        byte b = (byte)((abgr & 0x00FF0000) >> 16);
        byte g = (byte)((abgr & 0x0000FF00) >> 8);
        byte r = (byte)(abgr & 0x000000FF);
        return (a, r, g, b);
    } catch (Exception) { return null; }
}

• Option 2:
  • Good for theming (lets you choose from several colors) BUT you don't get your current theme color for some reason (I tried all the UIColorTypes)

public static Windows.UI.Color GetAccentColor(UIColorType type = UIColorType.AccentDark1)
    => new UISettings().GetColorValue(type);