Hmmmm Magic system based on colour is actually a pretty novel and somewhat intersting idea, at least to me. Manga is usually monochrome so it makes sense that it wasn't something that authors would go for so it's kinda fun to see it implemented in a coloured comic.
The question is, how close will they stick to this because so far if we look back it wouldn't really make sense. For example the magic that the blonde kitty girl used was purple which would imply the highest tier but it really can't be that strong, the magic attacks from the kinght dude are all blue but clearly the're not that strong either while the Vampire magic that was supposedly the strongest was red and by the graph that's the lowest tier.
Unless there'se something I'm missing here.