Likewise, trying to pick the "TUAW Green" for the text on the label, I thoroughly expected to see the standard Apple color picker so I could use the little magnifier tool to go for the green. No such luck. I finally figured out that I could option-click one of the custom colors to make the color picker appear (see below).
Hardware and Printing
Clicking the Print button in Discus brought up the standard Mac OS X print dialog with the DiscPainter pre-selected. I used all of the defaults and then watched as the blank CD was pulled into the tall part of the printer and slowly started inching out. It's cool to watch the printing, which occurs from the hub of the CD outwards. The colors matched those chosen in the software very closely, and the resolution was very nice (600 dpi). It took about two minutes for the printing to complete.
A DiscPainter with a slot-loader would make the footprint of the printer half the size of the current DiscPainter. One other gripe -- there's no power button to turn the printer off. You need to unplug it to totally power down.