Preheat oven to 350ยบ. Grease three 13x9x2-inch pans; line with parchment. Grease again, either with butter of cooking spray
Break up almond paste in a large bowl with a fork. Add butter, sugar, egg holks and almond extract. Beat with electric mixer until light and fluffy, 5 minutes.
Beat in flour and salt.
Beat egg whites with electric mixer until stiff peaks form in small bowl. With a wooden spoon, stir into almond mixture using a turning motion similar to folding.
Remove 1 1/2 cups batter; spread evenly into a prepared pan. Remove another 1 1/2 cups batter and add the green food coloring; spread evenly into second prepared pan. Add red food coloring to remaining 1 1/2 cups batter and spread into the last prepared pan.
Bake for 15 minutes, or just until edges are golden brown (do not overbake). Cake will be 1/4-inch thick.
Immediately remove cakes from pans onto large wire racks. Cool thoroughly.
Place green layer on jelly-roll pan. Heat apricot preserves; strain. Spread 1/2 of the warm preserves over green layer to edges; slide yellow layer on top; spread with remaining apricot preserves; slide pink layer, right side up, onto yellow layer.
Cover with plasatic wrap; weight with a large 1-inch thick plastic cutting board or object. Place in refrigerator overnight.
Melt chocolate over hot water in a small cup. Spread to edges of cake; let dry 30 minutes. Trim edges off cake. Cut into 1-inch square pieces. Behold and enjoy!