magic system where “dark magic” and “light magic” are literal terms - dark magic consumes photons, making an area around the spell visibly darker, sometimes to an Extreme extent, and light magic releases photons.

because of this most dark mages tend to work in very brightly-lit areas (either artificial light or outside in the daytime) to fuel their spells and wear and use lightly coloured clothes and tools so that they’re easier to see in the dimness their spells create, whereas light mages wear heavy, sometimes leaden robes (depending on the work being done) and the magical equivalent of welding masks to protect themselves from what can be an extreme amount of light, and sometimes other kinds of electromagnet radiation!

needless to say this is incredibly confusing for anyone unfamiliar with the culture