Why can we not make the color white when mixing pigments together?

Answer 1

White is when most of light at all wavelengths is reflected. Pigments make colors by selective absorption of *other* colors by the molecules within them. If blue, green, and yellow are absorbed, and only red is reflected, for example, the pigment is red. Mixing all the pigments together means *everything* is absorbed somewhat. That makes it dark.

Answer 2

The resulting color of a mixture of pigments comes from the chemical reactions between the substancies, not from the optical properties of the colors.

So don't expect to get white...

Answer 3

Paints absorb certain colors and reflect others. So, blue paint absorbs red and green, red paint absorbs blue and green, and green paint absorbs red and blue. When you mix them all together, they absorb all the colors and reflect nothing. Therefore, you get black.

White is the absense of pigment aka color absorption. It reflects all colors.

Answer 4

The pigments have colours due to their chemical properties and not due to presence of photons of different frequencies light.
White light is a combination of light of all frequencies in visible spectrum.
Pigments show colour due to electron jumps within orbitals, thus emitting energy in form of light in visible spectrum.