AITAH for implying my coworker can’t do something because she’s white?

I work at a daycare in a very, let’s say monochrome, neighborhood. I’m the only guy who works in a childcare role there. Sometimes I feel like my coworkers think I’m less competent because I don’t have those “natural maternal instincts” I’m always hearing about. There are only three people who work here that aren’t white, and one of them is me.

So there’s this little girl that I’ll call Suzy. She’s one of the very few black children enrolled in the day care. She got some paint in her hair. One of my coworkers, I’ll call her Melissa, took Suzy over to the kitchenette and picked up, I kid you not, the bottle of dish soap. I ran over, and said “Hey, woah, stop, don’t do that.”

Melissa gives me an annoyed look and explains like she’s talking to a toddler that Suzy got paint in her hair and it needs to come out. I said that’s all well and good, but you can’t put dish soap in her hair. It’s full of sulfates and will dry out her hair and make it brittle. She said “I think I know a little more about hair care than you do.”

I said “not black hair” and got the step stool for Suzy and wet her hair to soften the paint and then put olive oil on the spot and combed it out. Melissa looked angry and objected to the use of olive oil, saying it’s gross to put food in a child’s hair. Melissa also wanted to use a towel to rub Suzy’s hair dry, which I refused to let her do, ticking her off further. I took a T-shirt out of Suzy’s cubby and used it to squeeze the water out of her hair.

Melissa complained about me to our boss, who said it’s inappropriate to “racially charge” a situation that didn’t call for it. I said black hair is different from white hair and Melissa doesn’t know how to treat black hair. My boss said we don’t differentiate children by race, as that would be inappropriate and that all of the caretakers are qualified to take care of all of the children. She also said I shouldn’t be putting food in the children’s hair, which, whatever. I feel strongly that I was in the right, but no one is on my side. Am I the asshole here?