How-To
Preheat your oven to 360°.
Make the sugar cookie dough according to the instructions here.
Leave the dough raw; do not bake it. Separate the dough into three separate balls of equal size.
Work the food coloring into each ball of dough separately, using different amounts of red food coloring, or different colors, to create different hues. (We chose to leave one uncolored, but feel free to play around with different color combinations!)
Lay a sheet of parchment paper or plastic wrap down on a work surface, and flour it well. Separate the dough into rough teaspoons and arrange it in a patchwork pattern. Once you're finished, push them together so there are no gaps.
Place another piece of parchment or plastic on top of your cookie dough, and roll to 1/4" thick. You may still have small gaps - that's okay! Cut shapes from the pattern so each shape has some of each color of dough in it.
Carefully transfer the cut cookie dough to a sheet pan lined with parchment paper (chilling the cut dough before transferring helps this process greatly).
Bake at 360° for 8 - 10 minutes. Cool on a rack, and enjoy!