Mixing involve the wavelengths in the mixture and the perceived color results from what is . This is called color mixture. Mixing , which is called color mixture, involves wavelengths and the perceived color results from what is .

The answer to the question is as follows.

Mixing _lights_involve _adding up_the wavelengths in the mixture and the perceived color results from what is _added_. This is called __additive color mixture___ color mixture.

Explanation:    

Additive color mixing is the putting together two or more sets of different  wavelengths of light to form  light of a different wavelength hence a light of a different color. That is mixing primary light waves of different colors produces a secondary light wave of a different color by addition of the the wavelengths of the primary light wave.

On the other hand mixing of colorants  of different colors produces a mixture of the colorants with a new color by subtracting wavelengths of light.