Is this a chicken or egg situation. It seems most nectar laden flowers are of bright colors and tubular shape. Now we know that Aloes probably co-evolved with the sunbirds, since there are no hummingbirds in the old world. As aloes were planted here in the Americas the hummers have taken to them with relish. Not only the bright reds or oranges but the yellows, greens and whites. I think hummingbirds are not picky or extra sensitive to bright colors but just opportunists. Terry Hernstrom Redlands CA