I've found the best results using the black CD-R's and then marking the outer and inner edge of the disc with a green marker.
From: "Devious D_MasterMixer" <email@example.com>
Subject: Re: OT - Black CD-R's Or Psychoacoustics
Really, the bass sounds richer, the highs are clearer, I have noticed a better overall sound with the Black CD-R's. Maybe, it's just me, or maybe those CD's are just manufactured better ?