we have kitchen and sitting room tvs on the walls, sky box is under our portable tv in the bedroom.... both tvs have a magic eye. The tv in the kitchen has no power cables at all as plug behind tv but sitting room one has two cables running down from tv to the mantle piece, across right and down the side of mantlepiece and over the skirting up the wall to sockets. They are held in place with clips and wires are black so hardly noticeable at all. We did cut the plug off the tv wire and extend it to fit.
Family has tv on wall with white tube box over the wires, personally not my way to go.