Would it be Rainbow Gelatin Cubes? Found this in the April/May 2002 issue. Hope it helps.
4 pkgs. (3 oz. each) assorted flavored gelatin
6 envelopes unflavored gelatin, divided
5-3/4 cups boiling water, divided
1 can (14 oz.) sweetened condensed milk
1/4 c. cold water
In a bowl, combine one pkg. flavored gelatin and one envelope unflavored gelatin. Stir in 1 cup boiling water until dissolved. Pour into a 13 x 9 x 2 dish coated with nonstick cooking spray; refrigerate until almost set but not firm, about 20 mins.
In a bowl, combine condensed milk and 1 cup boiling water. In another bowl, sprinkle two envelopes unflavored gelatin over cold water; let stand for 1 minute. Stir in 3/4 cup boiling water. add to the milk mixture. Pour 1 cup of the creamy gelatin mixture over the first flavored gelatin layer. Refrigerate until firm, about 25 mins.
Repeat from beginning of recipe three times, alternating creamy gelatin layers with flavored gelatin. Chill each layer until firm before pouring next layer on top. Refrigerate for at least 1 hr. after completing last layer before cutting into 1 in. squares.
Yield: about 9 dozen