In one of his many lectures, I once heard Allan Watts talk about the colourful feathers of nature. He said that the animal and plant world is not necessarily so pompous and lavish in appearance and shape for evolutionary biological reasons, but also because beauty and colourfulness are fun. Not his words, but my interpretation. I don't dare to say whether there is deception in all the fuss, but I would guess that it would be human disappointment, for which the big and small critters really can't help :) I would treat aliens with far more scepticism, if only because of their unusual appearance. But I probably wouldn't see any at all at first. They say that what we don't know, we can't necessarily see right away ;-)