I have one Cornish Rex/Siamese/DSH crossbreed, bicolour (harlequin pattern), and one purebred Oriental Shorthair, who is blue.
They are both wonderful! To me at least
Radar, the Rex cross, is absolutely bonkers, very active, a little bundle of muscle and mischief, heavier than he looks, exceptionally soft fur (like the fluffiest baby rabbit you could ever imagine), is very affectionate but only on his own terms. He comes to me most for attention, prefers wrestling/playing rather than petting with people besides me, is very high energy, and if there is trouble to be had he will be right in the centre of it and loving every moment. He is completely, and I mean completely, fearless. This is the cat that when we first brought him home, firstly used the litterbox cos a cat's got to do what a cat's got to do, but then went to explore everything and mutilate his new humans. He chirps and peeps a lot but is generally fairly quiet.
Sonic (the oriental) on the other hand is very very affectionate and needy (partly due to his age, he is only 4 months at the moment!) he will go to anyone for affection, but was a little more timid when we first brought him home and didn't venture out of his carrier for 3 or 4 hours while he was getting used to his new surroundings. Once he'd come out of the carrier there was no stopping him, but he was a little less bold than Radar at first. Like many orientals, his voice is bigger than his body would suggest - he has a lot to say for himself, he joins in with conversations and talks back to you when you speak to him. Loudly
And when he's got something to complain about you know it for sure
I don't honestly believe that personality has that much to do with the colour of the coat - I think it has much more to do with breed and the start they get in life.