Color in Section

Okay, so I am very stumped.

Imagine you have a plane in UE5. The plane has a texture on it that looks like a coloring page. I want to know how to color in a masked area of the plane. I know there is a way to ‘paint’ in-game in unreal. What I don’t know how to do is confine the paint to a pre-masked area. I only want the pain to go in a specified area and not outside of it.

I’m totally stumped. Any suggestions?