maybe HDMI Cables do make a difference though, however reading a A/V mag they said its a waste of money the more expensive ones were.
maybe time to try a monster cable
What ever you do don't buy a Monster brand cable, don't feed him. Monoprice cables are just as good if not better and the only time you might have an issue regardless of what brand is if you have a long run, say over 12ft.
Color acurracy would be even bewtween plasma and a good LED lcd when properly calibrated at least the ones I have seen set up in some demo rooms.