After lining the wall behind my screen with 703 and putting my grill-cloth proscenium wall sections in place, I can see the yellow through the grilles in various places under certain lighting conditions. Some searches have revealed a number of solutions to the issue, from covering in felt (which I would think would effect the performance to some degree) to covering in another layer of grille cloth (more costly). I did not find any threads that broached the subject of the quickest/cheapest option - black spray paint. I tested a small area of one 703 panel and it doesn't appear to change the texture in any appreciable way, which leads me to believe it will not affect the sound, but before I ruin $150 worth of panels to save $50 in grille cloth I thought I'd post here and see if anyone had any reasons this might be a bad idea. Any replies appreciated.