Definition: Netscape color palette
A palette of 216 colors that render the same on all computer hardware. Also called a "Web-safe palette," the palette was selected by Netscape in the early days of the Web when many computers were unable to display more than 256 colors. Today, most computers support 16.8 million colors; however, the palette is still often used for absolute compatibility.
Where the 216 Came From
Giving red, green and blue (RGB) equal weight, the 216 comes from 6x6x6, which is the largest number cubed that goes into but does not exceed 256. 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.