GetThemeDocumentationProperty

[DllImport("uxtheme.dll", SetLastError = true, CharSet = CharSet.Unicode)]
public static extern HRESULT GetThemeDocumentationProperty(
   [MarshalAs(UnmanagedType.LPWStr)] string pszThemeName,
   [MarshalAs(UnmanagedType.LPWStr)] string pszPropertyName,
   StringBuilder pszValueBuff,
   int cchMaxValChars
);

Microsoft documentation: Link