RGB vs CMYK
Reproducing colors in screens or in paper is quite complicated, especially when you consider the number of possible colors. Screens use tiny LEDs that light up while printing uses various colors of inks. But it is quite impractical to have an individual LED or ink for each color. To reproduce the wide range of colors, most technologies uses three primary colors that are positioned very close to each other so that the eye mixes the colors together into one. But different media have different requirements, that’s why the RGB and CMYK color models were developed. RGB is used mainly in displays while CMYK is used in printing, each specialized to the media they use.
RGB (Red, Green, Blue) is an additive color mode. It is called additive because the background of screen is black. The individual LEDs then light up in varying intensity adding light to black. The variations in intensity of each color determines what color the user sees. CMYK (Cyan, Magenta, Yellow, Key or blacK) is subtractive because the paper where its printed on is white and the ink subtracts from the brightness of the white paper. CMYK also uses secondary colors that are much lighter than those used in RGB because to reproduce the darker colors, you would only need to add more ink.
Another key difference between these two color models is the use of black in the CMYK model. Although using only cyan, yellow, and magenta might be sufficient, there are some advantages to adding black. In order to reproduce black, you would need to add all three colors. But because they are light colors, you would need to apply the colors again and again. This wastes a lot of ink and soaks up the paper too much while the reproduced color is usually not black enough. Repeated applications can also lead to minor changes in the position with each layer applied which can make the image look blurry. Adding black as an additional color was the cheaper and easier solution.
Summary:
1. RGB is used to create images in screens and display while CMYK is used in printing to paper or other media
2. Both reproduces colors buy placing individual colors close to each other in order to fool the eye
3. RGB is an additive color model while CMYK is a subtractive color model
4. CMYK uses an additional color which is black rather than reproducing black by combining the three colors