Rainbow Citrus Cake - cooking recipe

Ingredients

3 1/2 cups sifted all-purpose flour
2 1/4 cups sugar
5 teaspoons baking powder
1 teaspoon salt
3/4 cup vegetable shortening
1 1/2 cups milk
4 eggs
2 teaspoons vanilla
1 lemon, rind of
1 orange, rind of, and
1 lime, rind of
yellow food coloring
red food coloring
green food coloring
12 walnut halves

Preparation

Grease and flour 3 (9 inch) cake pans. Sift flour, sugar, baking powder and salt. Add shortening, milk, eggs and vanilla. Beat at low speed 1 minute. Beat 3 minutes more on high speed (scrape side of bowl several times). Divide batter into 3 bowls; add lemon rind and yellow food color to 1 bowl; add orange rind and yellow and red food color to 1 bowl; and add lime rind and green food color to the last bowl. Stir each just to blend. Bake at 350 degrees for 30 minutes. Put layers together with lemon filling; frost top and sides with orange cream frosting. Garnish by placing the walnut halves evenly around the edge of the cake.
LEMON FILLING:
Combine 1/2 cup sugar, 1/4 cup cornstarch, and 1/4 teaspoon salt in large saucepan. Beat 2 egg yolks and 3/4 cup water with a wire whip until smooth. Cook, stirring constantly with a wooden spoon. Cook until mix thickens and bubbles 1 minute. Remove from heat, stir in 1/3 cup lemon juice and 2 tablespoons butter. Pour into glass bowl; cover with plastic wrap; cool completely. Spread between layers. If there's a store-bought lemon curd that you like, skip this step, and spread the lemon curd between the layers.
ORANGE CREAM FROSTING:
Beat 1/2 cup butter until soft. Beat in 1 package 10x sugar (sifted) and a dash of salt until all sugar is added. Beat in 2 tablespoon orange juice, 2 tablespoon corn syrup and 2 tablespoon vanilla until spreadable. Tint orange with red and yellow food color. Frost top and sides of cake.