Washed out colors are usually caused by configuring the levels wrong for that input. Computer levels are 0 to 255 whereas video are 16 to 235. If you set them wrong, you get the effect you mention. Don't see how the cable could cause that change though. If you had two inputs, one of them could have been configured incorrectly. Note that manufacturers have all kinds of funny names for this selection.
Both inputs were calibrated the same. When taking the pictures I actually swapped the cables within the same input.