In a bowl, beat together butter, sugar, egg, almond and vanilla extract, then beat in flour, baking powder and salt. Add a few drops of green food coloring until it reaches your desired green. Cover and refrigerate for 30 minutes.
Roll heaping tablespoons of dough into finger shape for each cookie. Press almond firmly into one end for the nail. Squeeze in center to create knuckle shape; using a paring knife or toothpick, make several places to form knuckle.
Place on lightly greased baking sheets or parchment lined baking sheets. Bake in a 325 degree oven for 20-25 minutes or until pale golden. Let cool for 3 minutes.
Lift up almond; squeeze red decorator gel onto nail bed and press almond back into place, so gel oozes out from underneath. Let cool.