Some discoloration can occur because televisions have marginal purity specifications, compared to computers. You can see some improvement by correctly setting the gamma setting. Here's how:
1. Open the Monitors control panel.
2. While holding down the keyboard's Option key, click the control panel's Options button.
3. Gamma settings will appear. Select the one for television, and the color should improve.
Gamma correction is used to match the computer color tables to the monitor or television set it is connected to. This is necessary because all monitors and television sets do not reproduce color identically.
Remember that the gamma setting for televisions is a "best guess gamma" because the gamma varies significantly from one television to another.