The 'standard' web visitor is using a 14" monitor set for 640x480 resolution and imaging 256 colors or 8 bits. (Back in '96 when I created this page.)   Windows and Macintosh use about 40 colors in their desktop setups.  Therefore, we can assume the imaging system used by most users will image 256 colors.  Subtracting the 40 reserved for the operating system, we are left with 216 colors.  The 216 color palette is best for most web design work.  Below is the Netscape 216 color palette.  It you have a color in RGB format and would like to convert it to HEX, please try the conversion script I have written.

Of course, the 216 limit is not as important as it used to be.  The 'average' user system now uses 800x600 and can view millions of colors.  Still, it matters. Cell phones, PDAs, laptops, and other devices using LCDs may not be able to render colors as you intended.  As always, consider your audience before venturing too far into the wilds of exotic colors.  LOL.

Hold your mouse over the color for the actual color code in hex.