"Actually," the swan replied, "I thought so, too, until I met a parrot. It had brilliant colours of red and blue. No other bird could be happier than the parrot."

It's no accident that Burger King, La Tasca, Sainsbury's and Waitrose use those colours in their branding or websites.

"There's no artist on earth other than Jasper Joffe who would have painted Himmler this way, using these brush strokes and candy colours," the collector remarked at the time.