You’ve probably seen them — those dreamy white-and-colour cats with just a splash of black on the head, or a tail like it was dipped in paint. They’re called van or harlequin, and their colouring comes from a gene called white spotting — or ws for short. But here’s the twist: Not every cat with this gene looks the same. Some have just cute little socks or a white belly…Others are almost completely white — and yet they don’t carry the gene for dominant white (w) at all. So wha