What are the primary colors from lightest to darkest?

Answer 1

There are three primary colors used in the fine arts, blue, red and yellow. We call them primary colors because they cannot be created by using any other colors and it is possible to make almost any other color by using combinations of them. Black and white pigments are used to lighten and darken the combinations.

The primary colors used in printing are cyan, magenta and yellow, plus black.

Regarding the above answer, while artists have long called blue, red, and yellow the primary colors, the actual primary colors are exactly the same for paint as they are for ink, dye, and any other material medium. This can easily be demonstrated by trying to actually mix, for instance, red and blue to get purple. The result will be unacceptable, but magenta and cyan in the right proportions will make everything from blue to purple. Doesn't matter whether you mix inks or paints; they are the same pigments.

So the surprising answer to your question in the most scientific sense is that magenta, cyan, and yellow each absorb exactly one third of the light spectrum and reflect the other two thirds. But in practice, yellow will be perceived as lighter than magenta and cyan. Magenta and cyan would seem about the same lightness depending on the product and the concentration and type of pigment it contains.