Add 1/2 cup cold water to each. Stir orange segments into lemon gelatin.
Pour into separate 8 inch square baking pans, chill until firm. Cut into 1/2 inch cubes. For each serving, layer parfait glass with lemon gelatin cubes, 1/4 cup marshmallow mixture and lime gelatin cubes. Top each parfait with remaining marshmallow mixture. 6 servings.