Preheat oven to 350°. Coat 3 9" x 12" pans with cooking spray, line with waxed paper allowing paper to come up the short end.
Break up almond paste in large bowl and to it add the softened butter, sugar, egg yolks and almond extract. Beat with electric mixer until light and fluffy, about 5 minutes.
Beat in flour and salt until mixed together well.
In a separate bowl, beat egg whites to stiff peaks then fold into almond mixture until well blended.
Divide mixture into 3 equal portion. Adding green coloring to one portion and red to another portion (leave the third uncolored).
Spread each portion evenly into individual pans until it covers the whole sheet in a thin layer.
Bake approximately 15 minutes until edges are golden brown. Remove immediately from pans using the waxed paper overhang.
Once cooled, spread preserves on green layer then stack yellow layer on top of green, spread preserves on yellow layer and stack red layer on top of the yellow layer.
Press down with large board gently until the layers stick together.
Melt chocolate and spread evenly over top. Let harden about 10 minutes then cut into 1 inch squares.