Page "Graphics Interchange Format" Paragraph 28

In the early days of graphical web browsers, graphics cards with 8-bit buffers ( allowing only 256 colors ) were common and it was fairly common to make GIF images using the websafe palette.

This ensured predictable display, but severely limited the choice of colors.

Now that 32-bit graphics cards, which support 24-bit color, are the norm, palettes can be populated with the optimum colors for individual images.