Does Bono (of U2) dye his hair?

I read that some people think Bono, the lead singer of U2, dyes his hair, but others are sure that he doesn't. I also read that he has had hair transplants, but according to U2 spokespeople, that is a false claim, so I no longer believe that he has transplants. But does he dye his hair? I know he did at one time, but does he still?