I Have a Problem with a Lcd Tv?

i have a 54" sanyo lcd tv, Just recently the tv seems to have lost its color a little bit. Its almost like the tv is not as bright as it used to be. Some tv shows seem fine but if i watch a movie or even a hockey game it just seems to dark. i have tryed every setting on the tv. What might be the problem

Suggestion:

if it has ABC….automatic brightness control,,,,,,,check this.