As members of the Red Alliance, an alliance set up to appreciate a certain Arthur Red Mane for helping them and to help other people who Arthur Red Mane helped, it is part of their customs to look like their role model, who happens to be Arthur Red Mane.
When they first established themselves 20 years ago, Arthur thought that they were an unserious fan club. He couldn't take them seriously when they dyed their hair to look like him.
He doesn't even have red hair anymore, so if they truly wanted to look like him, they should have dyed their hair green.
They were not accurately portraying him, so he thought that they were not a serious group of people. But 20 years has proven that they truly mean business.
Raor jumped over and cast a shadow over the three of them. The three of them looked up to see what it was that blocked the sunlight above them.