I had Hawkeye as my bonus hero for a long time and when I would get the rare bonus it was always purple. I do have 3* Hawkeye as my pretty much permanent only 3* bonus hero. With Kate Bishop I bonus her when I have all 4*s in tokens with at least 10 covers for shield training. So I've now got Domino as my bonus for awhile.I have Okoye as my 5* bonus now because she's meta and 4,5,2 with a saved cover. She's important to finish where as Hawkeye is more of a personal project.