Rainbow hair Underhair is amazing. I did it. New hair for the summer. Oh wait. It’s winter in Michigan. Well, I couldn’t wait any longer. I needed something to brighten my mood and have some fun. So, here I am with rainbow underhair looking like I am a Pinterest model for kick a** hair color. “I don’t care! I love it, I don’t care….” pop music listeners will pick up on that quote.