Colour Gamut Mapping for Painting

I wanted to write about gamut mapping or gamut masking as it is also called. I’m going to be exploring this method more in my colour painting studies from now on so I wanted to write about it to familiarise myself with the technique.

Gamut mapping is a technique for choosing a limited set of colours that work well together. It is useful for artists who use any medium whether digital or traditional. I will briefly discuss the technique and give links to other resources as well.

I first came across this technique after reading “Color and Light” by James Gurney.

James Gurney is one of my favourite artists. I first saw his art when I read the Dinotopia books as a child. James Gurney is an amazing artist and he is very generous with his sharing of artistic knowledge. I recommend you give him a look if you haven’t already done so.

His book describes how to make gamut masks using a colour wheel and the uses this has for an artist to create harmonising colour palettes. He has also made a short video on the technique here:

For a colour wheel that is more useful with gamut mapping you could use the Yurmby colour wheel. The Yurmby colour wheel was first created by Tobey Sanford. This colour wheel combines the RBG with CMY colour wheel and is a truer representation of how we perceive colour.

The technical explanation of why gamut masks create colour schemes that work well together is as follows:

The colours within a Gamut mask will harmonize with each other because the subjective primaries on the outer edges of a shape (a triangle with red, blue and yellow on the corners for example) will create the purest secondaries possible which will lie between the subjective primaries on the edges of the gamut shape.

The pictures in the following explanations were created using the online Gamut Mask tool. It also has a printable version which is useful.

The colours outside of the gamut shape mask cannot be mixed from the colours within it, so they are ignored or masked out on the colour wheel. This principle is also known as the CIE chromaticity diagram as described in this video:

Gamut mapping uses different shapes to select colours on the colour wheel. The chosen shape(s) can be resized, placed and rotated to select a desired gamut of colours.

Generally triangles are used, but other shapes can be useful for creating various types of gamut mapped colour schemes. If you used a triangle you would be creating a triadic colour scheme. I will describe a few of James Gurneys ideas here as examples, but I recommend you look at his deeper explanation as well here.

An equilateral triangle would create an “atmospheric triad” with a moody and subjective colour gamut. James Gurney suggests this would be good for a graphic novel or film.

A “shifted triad” is a shape that crosses over the centre of the colour wheel more. It looks like a long diamond shape.
You can also use a “complimentary gamut”. This selects a dominant hue range of colours toward the centre of the colour wheel and a smaller selection of its complimentary colour. James Gurney says this suggests an opposition of elemental principles such a fire and ice.
A “mood and accent” gamut uses analogous colours of a dominant colour and a smaller selection of the complimentary colour for the accent.
You can apply any colour harmony in choosing your colour gamut selections. For example monochromatic, analogous, complementary, split complementary, triadic and tetradic.
You can use any shape in any rotation on the colour wheel. Try shifting gamuts to the warm or cool spectrum of the colour wheel as well. This is a method of choosing colour you have to experiment with yourself to understand and get the most out of (as most art techniques are).

The shapes and maps you can use for this technique are unlimited and depend on the personality, mood or tone of the painting you want to create. Understanding how colour works is essential to any method of painting so it is worth trying.