I always paint my glass backgrounds black, cant stand the clear back and seeing the wall and everything behind the tank. And if your canister has black intake and outlets they will blend right in as long as your lighting isn't shining right down on them. Same with black heaters, but if your running that down in the sump then it's not an issue. You could run the canister on the sump tank as mentioned before to keep it all hidden, but you would probably need to raise the sump as the canisters are designed to be run below the water level.
