Light yellow...
I have a larger house (5 beds, 3 baths, 3 living areas, huge kitchen) BUT the laundry room is pathetically small for a house this size. (You have people to fill five bedrooms, they might have some laundry...)
Thinking of that small laundry room that the OP and I both have, I think that some of the colors mentioned, while fun, would be overwhelming in a small room. I have tried some very interesting colors in my house and using end up repainting pretty quickly. I never tire of the light, creamy yellow.