In my last post about colour I talked about some basics but I kind of glossed over something obvious. I don’t feel too bad about that because most 100-level art classes gloss over it too, sometimes for an entire year.
I’ve been talking about optical colour, the colour that you see. But of course as a painter you don’t work with optical colour, you work with paint. And paint is not light: paint is mud. Highly refined, industrially processed, very expensive mud, yes, but mud nonetheless. And while optical colour theory isn’t completely useless for getting a grip on colour in painting, the physicality of paint puts an interesting spin on how you need to approach it.
For example, you typically can’t change only one of value, hue and chroma at the same time. Mix a little white with your red: you’ve not only changed its value (it’s lighter), you’ve also changed its chroma (it’s less intense). You’ve also changed its symbolism: pink has vastly different associations than red does. This is what makes paint different than light, and hard to control: you have to know how to get what you want by mixing mud, not just adjusting the RGB slider in your graphics software.
The physicality of paint raises other issues that have no analogue in light, like thinness and thickness. Thin paint is typically more luminous, because in addition to light reflected off the paint you’re also getting some light reflected off the surface of the support (canvas, paper, whatever) so you get a kind of depth and richness to your color that isn’t there if you stick to thickly painted impasto. One isn’t better than the other, of course, it just depends what you want (though personally, I’d agree with Thomas Nozkowski when he says “paint wants to be thin”).
One urban myth about colour, that I heard repeated more than once in art school, was that only amateurs used all those different pigments you find in art stores. Real painters could mix any colour they wanted from a basic palette containing one red (cadmium red medium), one blue (phthalo, naturally), and one yellow (cadmium again). This is basically what happens when people who have no real experience working set themselves up as experts on the basis of something they half heard one time and misunderstood. What they were describing is called a ‘restricted palette’, and many painters have used some variation of it, although generally not the nasty one I just described. It’s one way to attain a kind of unity in your painting, since it basically ensures that all your colours will share common undertones. Stapleton Kearns has written some excellent notes on using restricted palettes.
However you can’t mix every possible colour out of a restricted palette; in fact the whole purpose of using one is to limit your range. As an experiment, try mixing a true cerulean blue from phthalo and whatever other colours you have kicking around. Even though phthalo is in hue not that far from cerulean, with phthalo you can only ever approximate a cerulean that comes out of the tube. That example points to why it’s important to become familiar with a wide range of available pigments, even if you don’t wind up using all of them, because having a wide range of pigments is the only way to have a wide range of colour options.
If that’s important to you. An awful lot of serious painters these days, particularly abstractionists, don’t use much colour at all; like maybe one per painting. Severely scaling back your colour gets around a lot of the challenges I’ve been describing here and in the earlier post, and austerity does have a certain built-in gravitas. Too much colour and you might be dismissed as a lightweight, too cheerful to be anything but a decorator. Like, say, Matisse.