A different colour format is required depending on whether you are looking at a colour on a screen or a piece of paper.
We are going to look at some science behind 5 commonly used colour codes in Design. RGB, Hex and HSL (web formats), and CMYK and Pantone (print formats).
RGB stands for Red, Green, Blue.
These three “primary” colours of RGB are the building blocks for all other colours in the RGB format. Each primary colour is given a number between 0 and 255.
If all three primary colours are set to 0, we get Black. If all three are set to 255, we get White.
RGB is an additive colour method.
What do we mean by additive?
Every RGB colour is formed by adding a certain amount of each of the three primary RGB colours onto a black background.
Since we start with a black background and we add colour, RGB is called an additive colour format.
This is opposed to subtractive colour.
We all learnt at school that the three primary colours are Red, Yellow and Blue, where Yellow + Blue = Green.
However, in RGB, it turns out that Green + Red = Yellow. This is because the light from a computer is additive not subtractive.
Since your computer emits light (rather than reflecting light from another source), the additive RGB colour system displays green and red light to create the illusion of yellow light.
The human eye cannot distinguish between natural yellow light and the mixing of green and red light from a computer.
However, it is important to realise that the computer isn’t actually creating yellow light. The computer is just creating an illusion of yellow light which is good enough to trick the human eye.