Recipe by jello.com 
How cute are these? Super fun for the springtime or for a Shabbos afternoon with lots of kids over. They not only look cute but taste great too.
1 package (2-layer size) white cake mix
1/4 cup dry Lemon Flavor kosher Gelatin (1/2 of 3-oz. pkg.)
1/4 cup dry Lime Flavor kosher Gelatin (1/2 of 3-oz. pkg.)
1/4 cup dry Strawberry Flavor kosher Gelatin (1/2 of 3-oz. pkg.)
1 container (16 ounces) ready-to-spread vanilla frosting
PREPARE cake batter as directed on package; divide evenly into 3 bowls.
STIR different flavor dry gelatin mix into batter in each bowl. Alternately spoon batters into 24 paper-lined muffin cups, adding about 2 Tbsp. of each batter to each cup. Bake as directed on package for cupcakes. Cool completely.
PIPE frosting onto cupcakes. (See tip .)