Have you used any calibration tools or utilities before on your TV, or does your TV, store the picture/audio settings independently per input?
And your LED TV, is it a full-array or edge-lit set?
Are you using an HDMI setup coming from you PS3, going through a receiver, and into your TV?
What I suggest, is that if you ARE running any type of HDMI setup from your PS3-out, ensure that you have the full-RGB HDMI setting turned ON, on your PS3, as well as the other full-color array options turned to ON, on your PS3. I noticed that playing with a few of the embedded PS3 video/display options on the XMB, I finally corrected some of the little things that bugged me about my picture/display, also
Just remember (or write down) the video/display settings on both your TV and PS3, and then start fluctuating with different combinations of settings, or changing things here or there, and go from there!
Good luck man!
(ps, check out AVS forums online and there are a TON of threads/topics on LCD/LED tv and PS3 display setup options/combinations.. That'll help too dude!)