8-bit color

8-bit color is a color depth that can allow for up to 256 grays, or 256 colors assigned by a color lookup table (CLUT). This is referred to as "256 colors" on Macintosh systems, and the VGA standard by PC users.

Color palettes
When the cost of was high, early computers used color palettes to improve the appearance of 24-bit color graphics through the 256 color limitation.

Apple Computer
Apple Computer implemented a "System palette" which included 6 levels of red, green, and blue in increments of 51 (on a scale of 0 to 255), that defined 216 uniform RGB colors. The remaining 40 colors were assigned to red, green, blue, and gray values that defined 4 gradients of 10 color values, and when combined with existing values from the 216, formed 4 smooth gradients of 15 values in increments of 17 (on a scale of 0 to 255).

Microsoft
Microsoft later implemented its own 256-color palette which assigned the first and last 8 values from its original 16-color palette, with the first 8 being half-luminosity values of the last 8.

Netscape
took the base 216 colors from Apple's System Palette, which closely approximated a subset of colors from Microsoft's palette to define the "" palette.