Web-Safe Colors in CS5
In the past, you had to conscientiously choose which colors you used on the web. Some computer monitors were limited in the number of colors they could display. Nowadays, color monitors are much more advanced and can handle a full range of colors, so images on the web are much more likely to be properly displayed.
Macintosh and Windows computers usually display your work differently because of gamma differences on these machines. Generally speaking, colors on a Mac appear lighter, and colors on a PC look darker.
Even though most computers can handle a full range of colors, you may have to consider color limitations.
If you’re designing a site specifically targeted at old computers or a certain user base, you may have to limit colors to the 256 web-safe colors, which means that any other colors used are approximated, which can look poor. If your site will likely be viewed by users with older computers, consider these suggestions:
Use a web-safe palette of 216 colors to design websites so that you specifically design with those older displays in mind and know what the pages will look like. This number is 216 instead of 256 because the lower number is compatible with both Mac and Windows computers. You can access this panel, usually known as web-Safe Palette or web-Safe RGB, from the Swatches panel menu in Illustrator and Photoshop.
Avoid using gradients, if possible. They use a wide range of colors (many unsupported in a limited web panel).
Avoid dithering if you can. A color that’s approximated because it can’t be handled by someone’s computer is dithered — the computer tries to use two or more colors to achieve the one you specified, causing a typically displeasing granular appearance. So a limited number of colors can have a negative effect on an image; notice the granular appearance on what should be the shape of a face in the figure.
If you keep the preceding suggestion list in mind, you’re ready to start designing for the web! Remember also that you don’t have to worry about using the web-safe palette of colors if you’re designing primarily for more up-to-date computers.