Muting Colors
Well, we already know what to do with primary colors. But what about mixtures?
Let's say I mixed red and blue, so I got burgundy, which is closer to red. So we take the opposite color to red, which is green. Green in small portions will mute red's intensity and make it more natural.
If we mixed blue and yellow, so we get a bright green, thus we add a drop of red.
In other words, we look at the dominant color of the mixture, and if it seems too bright, we add the opposite color on the color wheel.
But what if I don't have a mixture, but a ready-made orange, for example?
The rule is the same: we remember the color wheel and add a drop of blue for balance.
And what about violet? You can figure out yourself how to tone it down.
And again, don't forget to experiment.
Summary
If we want to mute a mixture, we need to understand its dominant shade.