The only thing I could think of apart from Easy Jet being orange but tha seemed too simplistic. I think other overseas airlines paint their planes different colours and Virgin is prenominately red.
I do recall one airline (Qantas?) advertising Lord Of The Rings on at least one of it's aircraft. Other than that, the only coloured planes i recall seeing are the ones in children's story books:-)
Many years ago I knew someone who used to fly for Court Line. She was the most outrageous crew member I ever knew and that was in the face of stiff competition.