Using a large pitcher, combine 1 quart water and grape powdered mix; stir.
Fill divided ice trays with all of the liquid. Freeze.
Repeat with lime and cherry powdered mixes.
To serve, fill clear plastic cups with an ice cube of each color. Pour carbonated beverages over cubes. Serve with a colorful straw. Children love to join in to help make this drink. When the cubes begin to melt, the drink looks like a rainbow.