For each of the 256 colors in a palette, there are three 8-bit numbers describing its appearance. (See Figure 9a.) Each 8-bit color component represents the amount of red (or "R"), green (or "G"), or blue (or "B") used to create a particular color. In HDF, 8-bit palettes are assumed to be organized as follows; each entry consists of three bytes: one each for R, G, and B value. The first group of three bytes represent the R, G, and B values of the first color in the palette; the next three the R, G, and B values of the second color; and so forth. Therefore, the 256 possible different pixel values in an image serve as an index for the 256 color entries stored in the palette.

FIGURE 9a - Color Mapping Using a Palette