I’ll just take a stab at answering this. The actual speakers are black, and a white face would not hide or mask the speakers as well as the black does. I am looking at my SONOS 5, and can make out the speakers’ frames, but not the black cones. I’m fairly certain they both would really stand out with a white front. I suspect most people would not like this, and for this reason the front cloth covers of speaker cabinets have traditionally been black. Black also hides dust/dirt better than white.