HD650s made after 2007 (I think) have drivers that are silver-coloured (the one on the right in the photo I conveniently found online). Apparently when compared to the old version, they are brighter and more balanced although I haven't personally compared the two myself.
P.S. I should mention that I paid GBP49 for the Q40s on the recent amazon.co.uk sale, a big discount from their usual price.
oh then I had the silver
Edited by grizzlybeast - 2/18/14 at 12:16pm