<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>
Under "Utilities/Options" pick the "Units" tab and in the area "Color Units" select the "0-255" radio button.
J<HR></BLOCKQUOTE>

Doh, now that was just too obvious for me to spot.
I was looking everywhere in the "Colour Gallery" for that one.
(I think I'll go stand in a corner with a pointy hat on!)