jeff-koons-colour system

The Science of Colour Systems

To get a better understanding of how to use colour in design work, we have to understand how colour works itself. Introducing… Science!


There are two main colour systems you need to understand as a designer. One is Additive the other Subtractive.

Additive Colour System

As we learned in the last post The Basics of Colour, colour works when light waves of certain frequencies bounce back into your eyes. The ‘colour’ of something is the property of the light it absorbs.

The Additive Colour System works by, you guessed it, adding additional light to a hue so that different light waves are viewed by your eyes.

For example, when you view the colour red, your eyes are picking up the red light waves bounced back. Same with blue. But add red light to blue light and you get…



But wait, if you look a little closer, you will see that your brain has actually been tricked and the object/image you are viewing is not technically magenta. You have been fooled, by Science!


Ok, I’ll stop that. Although your eyes view magenta, you are actually still just picking up red and blue light waves. However, this is enough to ‘create’ magenta as your brain cannot distinguish the different colours, creating a mix.

jeff-koons-colour system

If you look carefully at the Jeff Koons painting above, you will see how two dots of different colours create a third colour where they overlap. It is this overlap of lightwaves your eyes pick up and interpret as a new colour.

Subtractive Colour System

The Additive Colour System works by adding light, so  is used for screens and digital media. A close inspection of your computer screen will lead you to seeing how pixels are individual colours of red, green and blue moving and changing to create your display. But what about print media?


The Subtractive Colour System works by absorbing, or subtracting, the light waves reflected to change the colour viewed.  Where Additive Colour Systems start with darkness and add light to create colour, Subtractive Colour Systems start with all colours (white) and take colours away to give the impression of an objects ‘true’ colour.

Because Subtractive colour systems work by absorbing light, they are ideal for print and physical media.



Each colour system works on its own combination of ‘primary’ colours. For the Additive Colour System, red, green and blue lights are used to create colour. SO when working digitally, use the RBG colour system.

For Subtractive Colour System, the main inks used to create colours are cyan, yellow, magenta and key (CYMK). Key is black and used to darken a colour.

Now that we understand how colour is created using various colour systems, we can look at how to use colour for digital and print without making a mess or a mahoosive file size.

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