Preheat oven to 350 degrees F. Place liners into mini muffin pan.
In medium bowl, combine sugar cookie mix, butter, and egg. Drop by tablespoonful into 24 lined mini muffin cups (should put a little over 1 tablespoon of dough in each mini muffin cup.)
Press dough evenly into muffin cups. Use the back of a round-backed measuring spoon or a melon baller to make a shallow well in the center of each cookie.
Bake cookies about 10 minutes until slightly browned. Cool completely.
Divide can of white frosting into four small bowls. Add 1-2 drops of gel food coloring into each bowl and stir to make your desired shades.
Spoon each color of frosting into separate zip-top baggies. Snip the tip of the baggie and pipe the colored frosting into the middle of each cooled cookie.
Press colorful candies into the top of each Sugar Cookie Cup.