On work surface, place 2 pieces cooking parchment paper. Sprinkle a bit of the remaining flour onto 1 of the pieces of parchment paper. Use rolling pin to roll red dough to 8x3x1/4 inch. Transfer this dough to other piece of parchment paper. Repeat with orange, yellow, green and blue pieces of dough, placing each color on top of the other until they are all stacked in rainbow order--red, orange, yellow, green, blue.