I’m glad you brought up purple, meant to point something out: Red has a special association with green (traffic lights, avada kedavra/expelliarmus, caliborn/calliope from homestuck, etc) and that’s cause green is the rejection of red - it is made up of blue and yellow, the two primary colors adjacent to red. This is contrapositive to purple and orange. Purple: red and blue. Orange: red and yellow. Which means red can only combine with purple if it also combines with orange :hm Since white only has synergy with black, and red has synergy with all colors except secondaries, one could say that black brings out the purest tone of all the primary colors. In contrast white, because it is the source of all colors, represents the three color combinations because they create a hue closer to the origin.