Well first, lets say that there are color guns in the monitor that can regulate the intensity of a given color. There are normally three guns - RED, BLUE, and GREEN.

Combinations of color and intensities of the colors can be mixed to represent any color desired. Some monitors are capable of only 2 colors, others 4, 16, 256, and even some that can represent "true" color (or over 16 million colors).

Actually, you have no need for true color since you can't possible distinguish that many colors with your eyes, and it takes a tremendous processing power to calculate and display so many colors.

The color guns project beams of light (color) to various parts in a mix. These beams of light are called beams of electrons. They pass Through the deflection yoke in order to display them at the proper location on the screen. Your video card is responsible for sending the signals to the three color guns.

The beams from the color guns activate phosphor dots on your screen. The amount of power in each beam determines the intensity of that color. Remember, a pixel is a single dot on a screen, but the pixel is made up of the three colors. Different amounts of power for each of the three guns determines the color displayed as the three dots mix for the pixel color.