On aesthetics 
both polymaths, newton and goethe touched upon optics and the nature of colour
see a comparison paper : https://www.ideals.illinois.edu/bitstream/handle/2142/45848/18%20-%20Patriarchs%20of%20contemporary%20innovation%20-%20Newton%20%26%20Goethe%20-%20October%201%202013.pdf?sequence=2
goethe inspired nierzsche, who inspired the sujectivists, who inspired post modernists. the notion is that colour, through our umwelt is internally abstracted, and thus subjective depending on our abstraction.
the categories and modes of perception of man's cognition that are the natural products of phylogeny and thus adapted to the parameters of external reality.
They exist for the same reason as the horse's hooves are adapted to the prairie, or the fish's fins to the water. https://www.academia.edu/33408504/Evolutionary_Epistemology_The_Philosophical_Problem_of_Mathematics_-_Yehuda_Rav?fbclid=IwAR23fbOKOXMDpVup_0ojG-qRd3xBHfgOGvx6OwxrSQYmQ5CgPk3H5s87rPc