That's not your standard farmer's tan. I much prefer it, actually. His arms are all one color. T-shirt tans are so ugly. I have a slight one right now...ick. And I bet he did that thing with his hair to try and correct that bandana tan. He spent a few hours trying to correct some tan lines, that's all. I should be doing that as well.
All tennis players have tan lines. Socks, shirts, shorts...all of it creates serious differences in color. They could fix it by just playing naked, but they can't do that...for safety reasons.