A palette of 216 colors that render the same on all computer hardware. Also called a "Web-safe palette," it was selected by Netscape in the early days of the Web when many computers supported only 8-bit color and could render only 256 colors. Today, most computers support 16.8 million colors; however, the palette may still be used for absolute compatibility.
Where the 216 Came From
Giving red, green and blue (RGB) equal weight, the 216 is the largest number cubed (6x6x6) that goes into one byte (8 bits), which holds a maximum value of 256 (see
binary values). The 256 colors were divided by 6, yielding hex 00, 33, 66, 99, CC and FF, and any combination of R, G and B with these values produces a Web-safe color. See
RGB.