I recently inherited an HP Color LaserJet 2605dn printer. Which is awesome, because my old printer broke circa 2007 and I just never got around to fixing it. Anyway, here she is:

Pretty, right? And free! Unfortunately though it suffered from the dreaded HP Color LaserJet 2605 fading color issue. Black worked fine, but the colors were fairly faded looking.

Fortunately, this turned up on Google:

http://www.reeves-hall.net/tech-gadgets/fixing-washed-out-colour-on-hp-color-laserjet-2605/

Brilliant! This was exactly the problem I was experiencing, and a couple of hours of (enjoyable) taking the thing apart and putting it back together again it was printing beautifully.