You can try to calibrate your settings, particularly with the brightness setting. If the setting is too high, it can appear washed out - although on settings, the brightness setting is around 45-55, and should give a pretty good picture.

You might also check to see if your peripheral (cable box, game console, etc) doesn't have additional settings that might be working against the settings to create a "washed out" picture. Since you noted that it happens a lot with the cable box, you might try to have their customer service assist you with some of the settings that may be in the box.