Backgrounds can make all the difference to how an aquarium looks: they can be used to hide cables and equipment, create a more natural looking environment or simply bring out the colour of the fish.
The cheapest and most basic backgrounds are usually made from a sheet of plastic and are cut to size when one purchases them. These are usually attached to the outside of the aquarium. They are usually black on one side and blue on the reverse, or have some sort of print (often a planted aquarium, a marine aquarium or rocks). For aesthetic reasons, it is probably best to avoid the ones with the prints. The alternative to these are textured backgrounds, which go inside the aquarium, but these are often very expensive. Another option is to make a textured background for oneself, these often look best, especially for aquariums which are not heavily planted. Textured backgrounds are places inside the aquarium and usually imitate stones or tree roots.
My usual preference for backgrounds is plain black, so that is what I am using. Below are photos without background and with the blue background (which is looks lighter when not attached to the aquarium).
As can be seen from the photos, the light has a pink glow to it. This is quite unusual for me, as I usually use cool daylight bulbs (colour “865”). Most manufacturers which offer “aquarium” light bulbs, usually label pink ones as “plant”, although in reality, I think the colour of the bulb makes little difference, as long as the bulb is not green.