@BBsin I don't want to contribute to the cause, but I think it's been reported NUMEROUS times that GT uses a different TV/Brightness setting/contrast/etc etc. on Sony related products. I'm not sure why and it's not just this game, the same was reported about Assassins creed, it looked INSANELY dark on the PS3 version in their comparison, according to many it was actually lighter on the PS3.
The DS vrs. PSP video Leo posted not too long ago showed all the PSP games and I'll tell you, they looked HORRIBLE, far worse than the DS's graphics's wise which I think most of us know just isn't that way...
It woulden't surprise me if GT was using a different TV or setting for the comparison, there's been quite a few suggestions that they do.
From 0 to KICKASS in .stupid seconds.