ndex(), GrMapColorRGB()</PRE>
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Not all users have video devices which can display 256 colors at a time. Even fewer have printers capable of doing so. Therefore, the graphics system makes allowances for drawings which use unavailable colors. Exactly what the system will do with an unavailable color depends on the color mapping mode used. By default, the system will choose the two (or more) closest available colors and dither them together in an attempt to form a mixture which will appear to be the correct