What is RGB model colors?

To begin with, what is meant by RGB model colors? The RGB colour model is an additive color model in which red, green and blue light are added together in various ways to reproduce a broad array of colors. The name of the model comes from the initials of the three additive primary colors, red, green and blue.

To form a color with RGB, three light beams (one red, one green and one blue) must be superimposed (for example by emission from a black screen or by reflection from a white screen).

Everything has its own purposes. Well, the purpose of using RGB model color is  actually for the sensing, representation and display of images in electronic systems, such as televisions and computers, though it has also been used in conventional photography. Before the electronic age, the RGB color model already had a solid theory behind it, based in human perception of colours.

RGB model colours are usually used in photography, television and personal computers. Indeed, this model can be used in the t shirt printing together with CMYK model colors. However, to use this model colours must be depended on the devices that be used. The devices such as RGB and displays, video electronics, video frame buffer and etc are necessary to use this RGB model colors. 

Now, you do understand what is the RGB colour, right?

Sources: Wikipedia