His hair was changed to brown after his father, Steam dosn't allow porn games with the subjects involving "direct" incest so it's to make your realtionship with your housemate more "Vauge"
Boo
I downloaded the game and it's still red, it is also not on steam
The change is going to be implemented in future updates, and the change is for it to get ON steam. (it hasn't been processed yet)