Most instructions + some notes are in the game. Click on something to change its colour. Press space while your mouse is on something to reset it to its original colour. (There are a few where this doesn't work)
All credit for basically everything goes to Dress-up_games, the creator of the original. All I added was the pride flag, ponytail, and blank T-shirt. I was intending to add more but never got around to it, so I've just decided to publish it anyway because why not.