In the world of printing, there are endless arrays and shades of colors available to graphic designers. Unfortunately, and unbeknownst to many in web design, that is not truly the case when it comes to the web. While all of the colors of the rainbow can be used in a web design there are no guarantees that those colors will appear as the web designer wished if the colors aren’t considered to be a part of what are known as “browser safe colors.”
The browser safe colors have been known by a variety of different names over the years but some of the more popular are the color cube, the 6x6x6 cube or even the Netscape palette (which should give you an idea of how old this concept really is). The 216 colors that make of the color cube were established during a time when many computers on the web could only handle 8-bit color displays. This limited the palette to only 256 different colors, which is why the list of browser safe colors was established to insure backwards compatibility with older displays.
Browser safe colors are sometimes referred to as the 6x6x6 cube because the 216 colors that are considered safe are made up of 6 different shades of red, green and blue. There’s some mildly intense mathematics behind all of this that only a computer scientist could probably love. For anyone familiar with RGB or Hexadecimal settings in relation to color selection you will notice that all of the colors called browser safe contain combinations of 0, 51, 102, 153, 204 or 255 in RGB and 00, 33, 66, 99, cc or FF in Hexadecimal.
As time moves on, the important of browser safe colors becomes less and less significant in the grand scheme of things. In more modern times, it is very difficult to run across many displays that don’t have support for more than 256 colors. The only possible exception to that rule would be some brands of handheld and mobile devices but even that is changing rapidly.
It is still important to make your web design efforts as accessible as possible to as many people and devices as you can. Using colors that are considered browser safe is simply one way to help make that possible. It is at the web designer’s discretion if he wants to limit himself to the 216 colors defined as safe by Netscape years ago. If not for the concerns over accessibility, at least as an interesting exercise or challenge in web design. Sometimes limiting your choices makes it easier to come up with a great color scheme and design.