Color mixing in theory
A color wheel is a theoretical construction in which you have taken the spectrum of white light, from red to warm blue, bent this into a circle and filled in the colors that are missing in the spectra of white light, namely the violet colors.
There are different ways to arrange the colors in such a circle, there is no right or wrong in this regard. Some place red at the top of the circle, probably because it is the color with the lowest wavelength. Red is, so to speak, the first color in a series of different colors in a spectrum.
There are color wheels with violet, green or orange on top. Personally, I prefer a color wheel with yellow at the top because it is the lightest color, it feels right to have the lightest at the top and darkest (blue-violet) at the bottom.
Three colors are special because based on them you can mix all intermediate colors. These are yellow, red and blue. All of these are cold, that is, the yellow is a bit in the green direction, the blue is also greenish and the red has a pink hue.
In the printing industry, the colors are called yellow, cyan and magenta. These are the three so-called primary colors.
Between the three primary colors are all intermediate colors. In my example, there are five colors between the primary colors, but in reality there are an infinite number, without a border between different colors.
If you mix yellow and blue, the result will be some color between these two. With a lot of blue and only a little yellow, the mixture becomes blue-green (turquoise) with a lot of yellow, the result is green-yellow. All mixtures work the same way with two different colors, they always give an intermediate color.
In the middle of the circle there is black, the closer to the center of the circle a color is, the more black it contains. In the same way it is with whitish colors, the further outside the periphery of the circle a color is placed the more white the color contains.
When two colors are mixed, they can only produce colors along the line between those colors. This means that two colors that are far apart in the color wheel give a blackish mixture (unclear) while two colors that are closer to each other give a pure color as a result.
If you want a pure color as a result of a mixture, choose two colors that are close to each other in the color wheel. If you want the result to be more unclear, the colors should be far apart.
The further apart two colors are, the more unclear the mixture becomes. If two colors are so far apart that they are opposite each other, they are called complementary colors.
The result of a mixture of two complementary colors is black, they cancel each other out. The most common way to mix black with two colors is blue + brown (unclear orange) or red and green.