Mystery Hunt 1996 / Puzzle 1B Solution

If you look at the colormap as a 16x16 grid (as shown in xv) and you look at each color component separately (an easy way to do this is to set the gamma value for a single component to 1000 and set the gamma value for the other two components to 0) you get:

Red   - SHO
Green - EPR
Blue  - INT

For an answer of SHOEPRINT.