That oddly American holiday known as St. Patrick's Day is approaching and green will be the It Color for at least one day. Green beer, green milkshakes, rivers and hair dyed green. Offices become a sea of emerald dresses and olive sweaters. My own weakness for green is of the ceramic variety. Tall or squat, rounded or angular, there is rarely a green pot or vase that I don't find ravishing. In the 1890's, the cucumber-skin glaze created by the Grueby Faience Company ignited a craze for green pots. Every company developed their own version. Some are satiny and some are matte finish. Others are pitted and thick, like lava that has burbled up from a volcanic eruption. I've held, petted and admired the real thing in antique shops. My corner cupboard is crowded with new and old pots, but nothing that would reside in a museum. Celadon, emerald, spruce, leaf, I celebrate everything green.