In China, people believe that eating soy sauce makes our skin become dark or even tan because of the melanin. Well, it is actually not true. Also many people think that drinking coffee affects our skin.
Many people suppose that coffee is the "main culprit", this is a wrong idea. Actually, the prime reason that the skin of the youth becomes dark is insufficient sleep. Nowadays, most young people like to stay up late. Even though they are sleepy, they incline to drink some coffee to remove fatigue from their bodies rather than go to bed. It causes them of insufficient sleep and worse metabolism, this is the reason why their skin tarnishes and become dark. So it doesn't make any sense that coffee makes you tan. Meanwhile some analysis from the experts indicate that drinking appropriate coffee can improve your metabolism, expel toxin.
Besides to sientific analysis, one way valve think practical example is more persuasive to prove that the idea "drinking coffee makes you tan". For me, a coffee lover who drink a cup of coffee for an hour everyday, I don't feel that coffee is corasening my skin. Moreover, I observe that many friends of mine are all fond of drinking coffee, so I made a simple survey which shows that drinking coffee doesn't make us tan.
In sum, you don't worry about your skin issue by drinking coffee.