The main colors are red, blue and yellow. So why does a computer screen consist of red, blue and green, instead of red, blue and yellow?

Answer

Hi Jonathan,

There are 2 ways to mix colors: additive and subtractive.

Additive means that colors are mixed by adding types of light. Eg: on a TV screen red, green and blue light up to create the colors.

Subtractive means that colors are created by extracting colors from the white ambient light. This happens, for example, when using paint or ink.

The primary colors (main colors) in the additive system are different from those in the subtractive system. In the additive system these are Red, Green and Blue. In the subtractive system these are Yellow, Cyan and Magenta.
When using paint it is quite difficult to mix the right colors. The correct main colors for painting can not make them that long. That is why, for example, 2 types of red are used, depending on the color that one wants to obtain. To make colors darker or lighter, black and white are added.

So we can say that Red, Green and Blue are used as main colors in TV screens. Yellow, Cyan and Magenta are used as main colors when using paint and ink (see also the color strips that are sometimes used as a check on the edge of a leaf in a newspaper). However, because it is difficult to mix colors in this way, different shades of red are used instead of Magenta, and different shades of blue are used instead of Cyan. Many people also refer to cyan as blue.

If you have a color printer at home, you should check it out. Its main colors are Yellow, Cyan, Magenta and Black. These 4 colors together are sometimes called CYMK (Cyan, Magenta, Yellow, Key).

Kind regards,
Luc.