Why did artists of the renaissance rely on mathematical formulas?

Well you didn't give me the choices, but here goes. frigid means basically "very cold." while balmy is the complete opposite and means "warm and  humid."

White: titanium white.black: mars black.red: primary magenta, quinacridone red or alizarin crimson, cadmium red light.yellow: primary yellow, diarylide yellow, yellow ochre.blue: primary cyan, ultramarine blue, phthalocyanine blue.orange: pyrrole orange or cadmium orange.green: permanent green.

He could go with d. temperatempera coloring is very precise and can easily be used if you have the skills necessary to paint hair. this was commonly seen in religious paintings made with tempera techniques. the first tree are not that much about fine details and photorealism and are more about vivid colors and expressiveness.