Actors change their personal appearance about as often -- or sometimes moreso -- than they change roles.

Sometimes, however, they've rocked one look for so long that it can come as a shock to learn that what you once thought was genetic is, in fact, the result of having a very talented colorist on speed dial. Case in point: celebrity redheads. Some are real and some have just been faking it for so long our brains have taken it as law.

Can you tell the real redheads from their bottle-born counterparts? It's not as easy as you think.