The Duchess of Cambridge showed her fun side when she visited Oxford as part of The Art Project. She wore a gorgeous winter coat dress with a Dove Print by Irish designer Orla Kiely..,and promptly sparked yet another sell out. She also again showed her thrifty side by wearing another dress purchased at a sale price. The Birdie wool Jacquard shirt dress in Walnut has proved to be an instant sell-out, both in the walnut shade that Kate wore, and also in the turquoise shade. In fact, all the dresses that feature this print have now sold out, another sign of the positive effect Kate holds over fashion at the…