Another thing to maybe do is have a fiddle with the picture settings in the menu. I know on my Sony TV when I purchased it everything was on the vivid setting which is fine for the bright lights and glare of an electrical shop, but retina burning in the confines of your lounge, tweak the backlight down, ditto for the brightness and contrast. On my TV now I think every input going into it is tweaked differently to suit the appliance.
PS Treat yourself to a Scart lead or Component (if your feeling flush

) as composite is the least satisfactory of the picture outputs.