What may happen if too much black is added to acrylic colour?

Correct answer: The colour may look heavy and lifeless

Black absorbs much of the light and strongly lowers the value and perceived brightness of a colour. When too much black is mixed into acrylic paint, the original hue can lose its clarity and appear dull, heavy, or lifeless. Option D is correct. Black does not make the mixture lighter or brighter, and it does not automatically make the colour transparent. For controlled darkening, add a very small amount at a time and compare the mixture with the original.