What does it mean when a person has orange/ brown teeth?

Drug staining: Sometimes, people have staining on their teeth from being given certain medications before their enamel has fully formed on their permanent teeth. Tetracycline antibiotics are famous for causing grey/brown teeth. However, orange/brown teeth can also be seen in a rare genetic disease called porphyria (guther's disease). I would see a doctor to have this checked out.

Teeth are dirty: Time to call a dentist for an examination and a professional cleaning.

Tooth Discoloration: Teeth have not been cleaned properly, and the accumulated dental plaque can produce orange/ brown or yellow color. A professional dental cleaning at least twice a year can improve your oral health, general health and prevent tooth discoloration.