Netscape: The Dithering

Netscape color grid By default, the Unix version of Netscape 1.12 dithered everything except its background plane using a color grid of 125 colors in quarter RGB steps.

Consequently, a color you pick directly from this grid won't be dithered, unless there's another dithered color near that bleeds into it.

On Macs and PCs with a fixed 256 color table, a 6x6x6 color cube was used instead.

The Unix Netscape 2.0 color model on systems with 256 colors has so far withstood rational analysis, but has been reported to use a 5x6x6 color cube on alternate Fridays.

The 6x6x6 cube appears courtesy of Rick Levine's introduction to Netscape Color Tables at Sun.
Victor Engel has a very nice page of ``non-dithering'' Netscape colors, and of technical discussion around the phenomenon.