Everything in the Fire Nation must be red.

Standard disclaimers apply.

Azula took a good look at her surroundings. Everything was red: the walls, the ceilings, and the floor; whether it really was red or because of the battle that had just taken place, it was rather hard to know. Then again, in her opinion, red was pretty much the primary color of their nation. And whatever was red would fit in.

Just like the five figures sprawled on the floor.

They certainly weren't wearing red—save the tall young man with a scar on his face—but they certainly do fit in. Probably because there are more people on the floor like them, or that their clothes were stained by blood.

She thought that it would be very hard to remove those stains. But for her it's alright. At least now, there's no need to convince her father to accept the scarred young man before her—her own brother of whom she thought of and deemed as weak, worthless, and idiotic—because he already fits in. And so does his friends.

And that is all because of one thing she learned by using common sense.

Everything in the Fire Nation must be red.