I am in the process of finishing my daughter's room in the basement. She is an artist. I would love to give her walls to color on, but when the cost of the pain

I am in the process of finishing my daughter's room in the basement. She is an artist. I would love to give her walls to color on, but when the cost of the paint is as much or more than the rest of the room combined, it aes it hard. I've thought about aconite, but then I'm left with seems all over the room (but I don't have to mud and sand ;). There has to be a better way.