I always thought the numbers on the field side were more for stadium personnel/emergency crews to better identify when on the field where they need to go. Doesn't hurt to have that extra bit of info.
Also, DGAF about the back of it. The wall was always supposed to be to help make the stadium look better from the field for TV and for the the people on the field, not the field from the stands, and when you have people sitting in a game, literally the only people who will notice will be those right freaking there. If they paint it a matching color on the back, you'd really not notice it until you literally sat there, and after all how goddamn often will you be looking at the back of a wall when a rough ridin' game is going on. For Christ's sake I half forget we have a cruise ship of a awesome pressbox next to our stadium during the game cause I have very little reason to look up towards it, and I love our WSC.