A gamut is a range of colors. More specifically it is a range of colors that can be created or reproduced on a particular device or with a certain set of beginning colors.
Those working with print reproduction are very familiar with the concept of the CMYK gamut, or the range of colors that can be reproduced using traditional Cyan, Magenta, Yellow and Black printing inks, a smaller subset of the colors available, for example, on a computer monitor.
It’s not a term that painters use as often, but “gamut” also applies to a painter’s palette. When starting from a particular set of colors, the gamut is the range of colors that can be produced by mixing those colors (usually with the addition of white).
You will often hear me mention a “carefully controlled” or “limited” palette when talking about specific artists, particularly those working in film and gaming concept and visual development art, where limited gamuts are used to dramatic effect.
James Gurney, a highly experienced artist who works both with paintings for reproduction and for easel painting, has posted a series of articles on his blog, Gurney Journey, that delve into this often misunderstood aspect of color choices.
His recent posts on the Gamut Masking Method, (Part 2 and Part 3) carry the principles into the creation of variations in color scheme for alternate versions of the same painting, making the process even clearer.
The most recent post, Part 3, Gamut Masking Method is particularly informative in that Gurney has included an excellent short video in which he explains the essential principles of gamut masking in a demonstration.