What usually results from overmixing complementary colours on a wet acrylic surface?

Correct answer: A dull or muddy mixture

The governing colour-theory principle is that complementary colours oppose each other on the colour wheel. When they are repeatedly mixed, their strong chromatic qualities partially neutralise one another, often producing a lower-intensity brownish or greyish result. Therefore option B is correct. A clean bright colour is more likely when colours are kept separate or mixed briefly; overmixing does not create pure white or metallic shine.