What produces the different colors seen on a television screen?

A color TV produces the three primary colors of light.

Red, Green and Blue.

If all three colors are produced (nearly equally in strength) the perceived color is White.

By varying the brightness of the three colors all colors can be produced.

Try it yourself by using a magnifying glass on a working TV. Use a black and white picture (or turn the color control down). Although you see a black and white picture at a distance, close up you will see the individual colored dots.

On an LCD TV or monitor, the three primary colors are printed as filters on a plastic screen. The light is controlled by Liquid crystal shutters, in a glass panel behind, which are controlled by the electronics. The shutters control the amount of light let through from the white Light panel behind.

The light source of the illumination panel is provided by florescent tubes or white LED's