public void Screen()
        {
            Assert.True(Rgba32.Screen(Backdrop, Rgba32.Black) == Backdrop);
            Assert.True(Rgba32.Screen(Backdrop, Rgba32.White) == Rgba32.White);

            Rgba32 screen = Rgba32.Screen(Backdrop, Source);

            Assert.True(screen == new Rgba32(204, 163, 153));
        }