The next implementation of ColorModel.getRGBdefault() is not thread-safe:

    private static ColorModel RGBdefault;

    public static ColorModel getRGBdefault() {
        if (RGBdefault == null) {
            RGBdefault = new DirectColorModel(32,
                                              0x00ff0000, // Red
                                              0x0000ff00, // Green
                                              0x000000ff, // Blue
                                              0xff000000 // Alpha
                                              );
        }
        return RGBdefault;
    }