Cream sugar, butter, eggs and vanilla. Stir in flour and salt. Divide dough into 4 epual parts. Mix a few drops yellow food coloring and the lemon peel into one part. Mix a few drops green food coloring and the lime peel into another part. Mix a few drops each red and yellow food coloring and the orange peel into another part. Leave last part plain. Refrigerate covered at least one hour.

Shape each part colored dough into a roll 2 inches in diameter. Divide plain dough into 3 equal parts. Roll each part into a 6x4 rectangle. Wrap one around each of the colored dough. Roll each in matching colored sugar. Wrap and chill at least 4 hours.

Cut rolls into 1/8" slices and cut each slice in half, place on ungreased cookie sheets and bake at 400 F 6-8 minutes. Remove immediately from cookie sheets and cool.