The major browsers, Netscape and Internet Explorer, use the same palette-management process to pull colors from the system palettes. So, if you specify colors by randomly choosing by favor, those colors will be forced by browsers to display incorrectly using the color in the system palette.
How do I know which colors will not change when they are viewed on different machines?
The 216 web colors are in the form of 00 33 66 99 CC FF.
|This is 216 colors -- "CCCCCC".||This is not 216 colors -- "C0C0C0"|
|This is 216 colors -- "3366FF"||This is not 216 colors -- "3366CF"|
|This is 216 colors -- "FF99CC"||This is not 216 colors -- "FC99CC"|
The numbers that are put together like the above example are called "Hexadecimal Colors" (Hexa=6). You cannot select these number from your system palette, but you can specify RGB value in your system palette. RGB is red, green, and blue value. These numbers are used to convert RGB values to Hexadecimal values.
Next time you specify colors for background, text, or graphic images, make sure you're using these 216 browser-safe colors.
Perhaps you would like to use these 216 colors to create graphics for your page. Do you need to manually specify the numbers?
No, there are some places on the net where you can get the image, color lookup table (CLUT), and palette that contains the 216 color values. Please check below.
Lynda's ftp site has several copies of CLUT files to use with Photoshop, Freehand, Painter, etc.
Tom Venetianer's site has Netscape's 216-color palette for download to use with Photoshop.
Adobe's site: You can download a nondithering palette containing the 216 colors for Mac and Windows to use with Photoshop. These palettes were created originally by Lynda Weinman.