Here’s my personal opinion, it’s more of a color symbolism analysis than color theory tho
spoiler?
I think the color schemes of the pixie team is straightforward, every color represents something associated with the sin (for exemple red that’s associated with anger, purple that was the color reserved for the rulers back in the Roman Empire)Now when it comes to Shyloh (gluttony) yk how black is the absorption of light and in the story he is the villain because « he will absorb everyone’s ehsas » or something like this idk I didn’t play for a long time
For Sev I think their color is white. I mean it ties into their medicinal background. For me, their color is white but more like a blank canvas rather than the traditional associations of white in western culture (purity etc). They haven’t been allowed to develop their personality, and have hobbies other than what their parents want. So they’re kinda a blank canvas