GIF Images and Bit Depth: Color Shift

Properties	Image	Palette (adaptive)
8 bit 256 colors 46.3 kb
7 bit 128 colors 36.2 kb
6 bit 64 colors 28.9 kb
5 bit 32 colors 21.9 kb
4 bit 16 colors 16.5 kb
3 bit 8 colors 10.9 kb
2 bit 4 colors 7.31 kb
1 bit 2 colors 2.84 kb