It is often said that you can create every colour by mixing the three primary colours: red, yellow and blue in different ratios and combinations. What usually isn’t mentioned, however, is that undertones are something to keep in mind as well when mixing colours.
Primary & additional colours
In the Amsterdam acrylic colour range, we offer sets with both primary and so-called additional mixing colours. The primary colours Primary Yellow, Primary Magenta and Primary Cyan tend to be a bit cooler, while the additional colours Azo Yellow Light, Naphthol Red Medium and Ultramarine create a warmer colour palette. The sets also contain white and black to help you create different shades of the colours you mix.
Though both sets contain red, yellow and blue, the cooler colours have blue undertones whereas the warmer colours have red and yellow undertones. Using a six-colour mixing system allows you to create colours in any colour temperature, giving you more options than with a three-colour mixing system.
Selecting the right colours
To create bright, pure colours, select colours with undertones that don’t “pollute” your desired colour. For example, if you want to create a nice, bright violet, you should opt for Magenta and Cyan as they both have blue undertones.
If you were to mix Naphthol Red Medium with Ultramarine, you would still get a purple colour, but since the red has a yellow undertone to create a warmer colour, the purple will turn out a bit more yellow as well. This makes the colour duller and not as vibrant as it could have been using colours with blue undertones.
Using just the primary colours, you would not be able to easily create a bright orange, for example, since Magenta has blue undertones. Using the additional mixing colour Naphthol Red Medium and Azo Yellow Light, you can create a beautiful warm orange.
When mixing a cool-toned yellow with a cool-toned blue, the green that would come out is a bright, vibrant green. With the warm-toned colours, greens tend to lean more towards earthy brown or olive colours.
So yes, the three primary colours could in theory create every colour there is, but it is much easier to start with six as shown above! Or eight if you want the added benefit of black and white to brighten or tone down your colours. This way you can easily create a wide range of colours in all different colour temperatures and shades.