No support with hair dye

I want to dye the bottom layer of my hair red. I currently have white blonde hair but my boyfriend doesn't support the idea. He said that it is up to me, he doesn't want to hold me back from something I want to do. He doesn't really support any body modifications I want, such as a naval piercing. Or a tattoo. But he was making fun of me for wanting to dye my hair. What should I do? I don't want to go against his opinion and dye it but this is something I have been wanting to do for a long time.