Rainbow JELL-O Dessert Slices

boiling water, divided

pkg. (3 oz.) JELL-O Raspberry Flavor Gelatin

plain nonfat Greek-style yogurt, divided

pkg. (3 oz.) JELL-O Berry Blue Flavor Gelatin

pkg. (3 oz.) JELL-O Lime Flavor Gelatin

pkg. (3 oz.) JELL-O Lemon Flavor Gelatin