Algae Eaters have a some chameleon ability. They'll adjust their color slightly to match the ground, but it's subtle. They aren't going to change from green to brown like some lizards, but they can go from brown to black.
As far as algae... just buy some pleco pellets and drop one or two in at night (or whenever you notice the fish is active). You can also feed cucumbers.
Whatever you do... do not try to introduce algae. It'll show up soon enough, and then you'll have to deal with it.