Preheat oven to 350 degrees. In a large bowl, cream together the butter and sugar for about 1 minute. Add in egg and extracts and mix to combine. Gradually mix in flour and salt until all flour is incorporated into the dough.
Divide dough into the number of colors you want to dye your cookies (i.e. blue, green, purple, etc). Divide each of those balls of dough into thirds. Dye one third a dark shade of your color, one a light shade, and leave one plain.
Roll the balls into strips and twist the strips together. Roll out as normal so the dough is about 1/4 inch thick. Roll over it with an engraved rolling pin using a moderate amount of pressure.
Use flour to help the dough not stick to the rolling pin. Cut out the dough to the desired shape. Repeat with other colors of dough. Place on a baking sheet. Bake for 12-15 minutes, or until the edges are just barely browned.