Color palette and gradient screens

This test displays a color palette and one or more screens of gradients, whose smoothness is dependent on the color depth selected for this test.
Since DXGL Test uses a “default” palette there is very little smoothness for the 8-bit mode.
For 15, 16, and 24/32 bit modes, the palette is generated mathematically to display as many of the possible colors as possible on the screen.