Before her fearless demeanor, I remembered a story my master had told me. In the
Clock Tower, those with special abilities were granted Colour titles. Those who bore the
three primary colours were recognized clearly as the greatest of their generation. As
such, it was clear to anyone that Touko Aozaki would be crowned with the title of pure
Blue.
But she wasn't.
Rather than the primary colour of Blue, she was given a composite of red.
(Because she's...not the strongest...?)
For some reason, I felt like that was incorrect.
I didn't know a single magus approaching her level. Perhaps it was because she had
shunned the factional warfare within the Clock Tower, but that didn't seem to be the
case either. Was it because, like her hair, her soul itself burned a bright red? A colour
whose beauty derived from the fact it could never reach purity.

The Case Files of Lord El-Melloi II, Volume 3, Chapter 2, Part 3