Thinking about during readers relationship with mattheo riddle, their hair would be a really dark brown, any makeup would be to accentuate darker features, and all shades of dark clothing. Obviously mattheo would be incredibly / forcefully influential in their life, so his habits and hobbies would be made to become theirs too.
Post breakup reader has their hair a lighter, honey ish brown, soft makeup with a glowy highlight, and starting to find their own interests again like reading in the courtyard in the sun (I’m picturing under the tree Draco is in in goblet of fire)
I really think mattheo would be into the innocence of a hufflepuff reader, whether he wants to keep that innocence or he has a thing for corrupting them, I’m not too sure 🤷🏻♀️