After decades of coffee and red wine, my teeth should look dark, but they're actually ok. I think it's good care and dentist every six months that has worked.
You can use whitening strips, whitening toothpastes, stronger strips at the dentist, etc.
I see more people with REALLY white teeth now. Not natural, but gleaming. While they do look clean and healthy, I don't like the look. When you look at a face, the enamel shouldn't be the dominant feature.