Color

What we consider to be just a white light is actually a spectrum of the seven colors of rainbow. This can be demonstrated by projecting a beam of white light through a prism – the light breaks up into different colors. The converse is also true, and that is, if you mix all the basic colors of light together, you can produce white light. This concept helps to understand the key to the additive process of color television. As the name suggests additive process involves adding or mixing the colors together. Thus if you mix the additive primaries such as red, green and light blue, you get the white color.

Another concept that needs to be understood is the subtractive color process which means that the color of an object is determined by the colors of the light that it absorbs and reflects. For example, if the white light falls on the red object, the object assumes the red color as its surface absorbs or subtracts all the colors of the light from it except the red color.

If you want to produce black color you need to mix together the primary subtractive colors of cyan, yellow and magenta pigments. The experiment can be carried out further by mixing yellow and cyan to produce green. If you want to produce blue, you need to mix magenta and cyan.

If you place a colored filter or gel over the camera lens or light, you will find the same type of color absorption or subtraction. A pure blue colored filter fixed over the camera lens will subtract all the colors except the blue.
In case of additive process, the combination of blue, red and green will create white light. Red, green and blue colors are the primary additive colors of the TV. If you mix two exactly opposite colors on the wheel, you get the white light.

In case of subtractive colors, these colors do not cancel each other but combine with each other for an additive effect by complementing each other, i.e., combining with each other to make one whole.

It must be noted that opposite colors on the wheel tend to strengthen each other when seen together. For example, red color will appear ‘redder’ when placed next to cyan and blue color will look ‘bluer’ when placed next to yellow. This explains the reason why the redheads like to wear blue, green or blue-green clothes.