Why does blending all primary colors, make mush?

Question:In paint it would become a nasty brownish mush, but in therory it is black. That is because of the nature of paint. When you mix all the colours, as in light, they become white.
A rainbow is white light split in to all its colours.
Complentary colours also make black in theory, so orange and purple or blue and yellow, or red and green when mixed, become black in pigment or white in light.

Best Answer - Chosen by Asker: In paint it would become a nasty brownish mush, but in therory it is black. That is because of the nature of paint. When you mix all the colours, as in light, they become white.
A rainbow is white light split in to all its colours.
Complentary colours also make black in theory, so orange and purple or blue and yellow, or red and green when mixed, become black in pigment or white in light.

Well, no matter what you eat, it comes out mush, too. I guess too many dominant factors all just make a pile of mush!

because the primary colors you are mixing are not pure.

Mixing a pure Red, Blue, and Yellow should result in a black pigment.

Mixing Cyan, Magenta, and Green light should result in white.