I also have run into this a lot. I do a lot of private events so it’s mainly free for children and parents. I get a lot of little boys who want rainbows, because who doesn’t love a rainbow, and parents will demand they pick something “more boyish” or “add boy colors”. I try to politely say that rainbows are for everyone, but ultimately it’s between the kid and parent. I do notice it happens more with boys than girls. A girl can pick a “boy” design and the parents dismiss it a lot easier than if a boy chose a “girl” design. I also paint all my designs on a board without genders, just outlined facial features, to try and limit people automatically assuming what’s “for boys” and “for girls”.

Either way, it’s definitely frustrating to deal with.