Plain Planes

Why is it that we don't have more causal looking planes? Like Air Asia and Virgin have, just colour blast or graphically aesthetic designs. Wouldn't you want to look up into the sky and see something colorful and bright pass by? I'd have planes with incredible graffiti or vector designs all over, if i were ever to possess passenger airlines. Just now sure where to park em! A pair of Emirates flights come in view. Dxb, UAE.