THE COLOR of the new Cafe Patachou in the Stutz Building is Sherwin-Williams Halcyon Green, a restful green-gray that skews dusty blue in a certain light. Patachou owner Martha Hoover has used it in every bedroom in her homes for 40 years and leaned on the hue to anchor her two latest openings, the Stutz location and the Zionsville Patachou that debuted in August.