TV screens

[Potatoman]

If a pixel contains red, green and blue elements, how do they combine to make white? I cant work this out! Thanks for your help.

[Salamander]

Try this link

[Ralph]

Red, green and blue are the "additive" primary colours whereas you may be more used to the "subtractive" primary colours (cyan, magenta & yellow) that result when you mix paints or inkjet inks for example.
Have a look at http://en.wikipedia.org/wiki/Primary_colours for a better explanation than I could give.