Colors in a painting that are not what they seem to be?


I know color is an illusion and is only what it is when surrounded by another color, I’ve found articles about this, but none that explain how to control this phenomena. In this painting that I found online, by Marc Simonetti, it’s a good example of yellowish light with even warmer shadows. What appears as green shadows and local color, is actually ranging from yellow to reddish brown. How does one go about knowing what color to lay down to have this effect? I know neutrals are a powerful thing in a painting, I can only reproduce this effect after numerous and random attempts, I’d like to know how to control it a bit more and how’d I go about planning my painting for this effect. P.S. Is there a particular set of percentage of saturation in specific colors that make them look like another color, no matter the setting? I know from this painting, RGB: 173,170,136 is a yellow that looks like a green? I can’t seem to find a good explanation online on this.


This is one of the lessons I teach about in my workshop (see link in my signature below). There are specific exercises you can do to improve your ability to assess colors accurately, and there are ways to approach your painting’s workflow so you don’t even have to worry about this at all, as you’d be using a much more logical approach to color variations in your artwork.

What’s really important, more than anything else, is the way you think about color. In order to gain a strong grasp on colors, you have to think about them very logically, such as the effects of radiosity and how color bleed from bounced light changes the colors of surfaces they bounce onto. There’s also the natural variations that happen to the local colors themselves, such as how skin tone has warmer, more flushed areas with lots of micro blood vessels, as well as cooler areas where there’s a lot of fat and bone under the skin. There’s of course also the color cast of the light sources themselves and now they alter the colors of everything they illuminate. And once you’ve got a good handle on the logical aspects of lighting and colors, you can exert artistic license and alter the colors specifically for artistic effect. but usually you only push the colors that far in images that are meant to be very stylized, where the color choices no longer conform to the laws of physics (for example, using lots of vivid colors to paint a stylized, surreal-looking portrait, but none of those colors actually exist in the real-life counterpart).

When you are able to approach colors logically, it’s mainly just a matter of matching the colors to the laws of physics so they visually make sense (which often also means they look sophisticated and convincing). When thinking that way, you’re not concerned with whether you can easily identify/choose a color even when the surrounding colors are causing optical illusions and throwing you off. What you’re thinking about instead, is how that wall, which is painted blue, is bounding its color onto that red shirt, and mixing the blue with the red to create purple, but there’s also a yellow light source that’s also adding to the mix, further changing the color. If you paint with that logical approach and use the correct workflow (local colors first, light source color cast influence next, radiosity/color bleed next), you won’t have to worry about the stuff you asked. I explain all of this is far greater detail in the workshop.


I appreciate where you’re coming from and what you’re trying to accomplish, but must address the very first statement in your post. Color is NOT an illusion, not at all. Color is a real physical effect based on the photons themselves, and their properties. The quantum colors are red and violet; everything between (every other color) is an average of wavelengths and spins between those two primary colors. Including green. This is of course just the human-visible spectrum, expressed physically.

Read this short, simple paper sometime when you get a chance. Mathis explores and explains all color, through photon mechanics alone and outright. He’s a traditional portrait painter and physics student, and writes hundreds of papers on the topic of light, photons, and the physics involved. It’s simple stuff too - no heavy math, just some algebra on occasion.

RAINBOWS, PRISMS, and Non-Edge Diffraction
A Rehabilitation of Goethe

by Miles Mathis