Palettes can be used only on screens with 256 colors (or less) and allow to
'map' the colors displayed. It's possible to assign each color (indexed from
0 to 255) to a specified RGB color, choosen from a 24 bit palette (16
Millions colors). The advantage is huge, as all the pixels from a color can
be changed to another color only by changing its associated color. It allows
to do very fast palette cycling, fade-in, fade-out and other well know
effects.
