I got it. The problem was that I was using an unsuported display profile. In the display prefs, check the box that says 'Show profiles for this display only'. Choose one from that list, or calibrate to createa new one. It requires a reboot to take effect.
I was getting desaturated interface elements all over the place before I found the fix. Apparently, some 3rd party apps installed some new display profiles and they aren't compatible with Apple's HD dispay.