My favorite tanks I’ve kept were a small community tank with honey gourami, Bolivian Rams, and misc schoolers. A predator tank with Central American cichlids and bichir, and a brackish tank with archers, scat, and my Tiger Moray.
If you want a lot of plants I’d steer clear of the cichlids, mine tore them up. Not many purple fish in fresh water, but emperor tetras, peacock gudgeon, fancy guppies, some African cichlids, and of course the purple spaghetti eel can fit the bill.