Place rhubarb, sugar and water in a large saucepan; bring to a boil. Reduce heat; simmer, uncovered, until thick and blended, 10-15 minutes. Remove 3/4 cup mixture to a bowl; cool completely. (Save remaining rhubarb for another use.)
Add yogurt, applesauce and strawberries to bowl; stir until blended. If desired, tint with food coloring. Fill each mold or cup with about 1/4 cup rhubarb mixture. Top molds with holders; top cups with foil and insert sticks through foil. Freeze until firm.
Editor's Note: If using frozen rhubarb, measure rhubarb while still frozen, then thaw completely. Drain in a colander, but do not press liquid out.