Microsoft Windows name for 16777216 color mode; also X11 display class for the same color depth.

In TrueColor mode the color is expressed in 24 bits (3 8-bit bytes, one for each red, green and blue).

Usually this is as far as most monitors go. The reason is simple: human eyes usually can't even distinguish between that many colors... (then again, this - "no one can notice any difference anyway" - is the same argument some people used with MP3s, but I guess this point is more valid. =)