Dissolve: 2 envelopes Knox Gelatin in 1/2 cup cold water.
White liquid: 2 cups of milk - bring to a boil and add 1 cup sugar and turn off - let sit until cool
Add: gelatin mixture and 1 pint vanilla yogurt to milk and sugar mixture. Beat with hand or electric mixer.
Dissolve: 3 ounce box of lime jello with 1 1/2 cup hot water.
Pour lime jello into 13x9x2" pan that has been buttered or sprayed with Pam. Put in refrigerator. Set firm. After lime jello is set, pour 1 1/2 cups white liquid on top. Let set 20-30 minutes.
Dissolve another flavor of jello such as orange, pour on top and let set. Then add white liquid, lemon jello, white liquid, and finish with red jello on top. Always pour slowly and carefully so you will not disturb the previous layer.
(Any four different flavors of jello will work)