Paint the inside so it doesn't rot out. plain white will increase light stray light return.To make the outside pretty you can go to a craft store and get a centerpiece stencil to spray and make it stand out less. A strip of something glued on the inside will stop light from escaping the crack. Some little cabinet door knobies wouldn't hurt. If you buy rustoleum wood paint (not reg metal) it can be glopped on thick and smoothed with damp sand paper to get the plywood looking less plywoody.
Post pics as it comes along.