How may yellow acrylic colour appear if too much black is added?

Correct answer: Olive or muddy

The governing concept is subtractive colour mixing and control of value and saturation. Yellow mixed with a large amount of black loses brightness and purity, so it may become olive, dull, or muddy. Therefore, option D is correct. Pink would require red or magenta, orange requires red, and black cannot turn yellow into pure blue. Black should be added gradually and sparingly.