Mix 1 cup of boiling water with your first color of Jell-O.
Put 4-5 ice cubes in after the Jell-O has dissolved.
Mix until completely dissolved.
Take out 1/2 cup of Jell-O and set aside.
Mix the rest of the Jell-O with 1/3 cup of vanilla yogurt.
Pour the plain Jell-O mixture into the bottom of a 9x13 pan.
Refrigerate until set ; about 30 minutes.
Pour Jell-O and yogurt mixture on top.
Let it set in the fridge.
Repeat with all remaining colors.
Top with whipped cream or Cool Whip.