The 216-color browser-safe palette traditionally used in web design, popularized by Lynda Weinman. The browser-safe palette was developed when most computer users had 8-bit (256-color) monitors. (There are only 216 colors in the palette because the other 40 colors were reserved for the operating system.)
In their September 6, 2000 Webmonkey article, “Death of the Websafe Color Palette?”, David Lehn and Hadley Stern established that this palette does not consistently work across different browsers, platforms and monitor resolutions.
The colors in the browser-safe palette are made up of combinations of the hexadecimal values 00, 33, 66, 99, cc, and ff. All of the colors in the browser-safe palette are also in the web-smart palette.