In a bowl, combine the almond paste, marshmallow creme and corn syrup; mix well. Beat in the confectioners' sugar until combined. Turn onto a waxed paper-lined work surface; knead in food coloring. Divide marzipan in half. Roll each portion into a 10-in. circle between two pieces of waxed paper. Remove waxed paper; cut each circle into four wedges.
For each tree, place tip of marzipan wedge at tip of ice cream cone; wrap around cone and pinch edges to seal. With kitchen scissors at a 45° angle pointed toward the top of the tree, cut "V" shapes into the marzipan. Work from top to bottom of tree, then continue around the tree until completed.
Place a small amount of food coloring in a bowl; thin with water if desired. Brush over marzipan trees. Dust with confectioners' sugar. Use to trim holiday cakes.