I got a piece of pottery, after air drying with gouache or acrylic paint color, and then spray clear lacquer, this is okay?

I am an elementary school art teacher, usually have led the children to do clay works, I do not know what kind of your pottery, but we all use acrylic color, acrylic color itself after a certain luster, also tried to use transparent paint and then brushed again, but the color will be the overall yellowing, the effect is not very good, we recommend that you only use acrylic can be.