What effect is made by adding black to a colour?

Correct answer: Colour becomes darker

The direct answer is option C: the colour becomes darker. In visual art, adding black reduces the lightness of a colour and produces a darker version, commonly called a shade. The reasoning is: begin with a colour; mix black into it; the mixture reflects less light than the original colour; therefore it appears deeper or darker. Option A is wrong because a lighter result is usually made by adding white, not black. Option B is wrong because changing colour darkness does not automatically make a shape flat. Option C is correct because black deepens the colour and creates a shade. Option D is wrong because adding black does not increase the physical or pictorial space. The exact result can depend on the material and amount of black, but at this school level the intended effect is darkening. Memory cue: black makes a shade; white makes a tint.