The group of colors from which all other colors can be obtained by mixing is called primary colors. In paint pigments, yellow, red, and blue are the primary colors because they can’t be created by mixing any other colors and all other colors can be obtained by mixing them in various combinations. The three primary colors of light are red, green and blue.
The three primary colors of light are red, green and blue. In paint pigments, red, yellow, and blue are the primary colors. The difference is that light is additive, while paint is subtractive. If you mix all three primary colors of light, you will end up with white light. But if you mix all three primary colors of paint you will end up with black paint. With light, you are mixing wavelengths together, adding them up to some color. With paint, you are removing colors. For instance, red paint absorbs all wavelengths except for red. And if you have green paint, it will absorb all wavelengths except for green. So, mixing them together, you will absorb all wavelengths. This is why with light you want to use the primary colors- colors which are a single wavelength, while with paint you want to use secondary colors- colors which reflect multiple wavelengths. For instance, yellow reflects red and green, while magenta reflects red and blue. So, mix yellow and magenta together, and you'll get red (since yellow absorbs everything but red and green, magenta absorbs everything but red and blue, leaving only red).