Green parts of the uniform are to be changed to correlate with your chosen house.
Purple for Hades, Yellow for Zeus, Red for Ares and Blue for Poseidon.
Their house emblem can be found on the pin in the middle of their bows.
If your student is genderless, or both genders, feel free to choose one or the other.
You are also free to tweak the uniform in order for it to fit your characters race.