Mix the cake mix, eggs, and oil together in a bowl. Once well incorporated, split the dough into two separate bowls.
Then, color each bowl with food coloring, one with green, and the other with red. Use as many drops of the coloring to create the desired color. I suggest doing a couple drops at a time.
Once the dough is colored, refrigerate for 30 minutes. This will help make the cookie dough easier to work with.
When dough has chilled, take it out, and roll into small balls.
Roll the balls in the powdered sugar. I put the sugar into a small bowl. Coat the balls generously with the sugar.
Place on cookie sheet, and bake at 375 degrees for 8-10 minutes. You will want the cookies to be a little firm, but still soft. Baking time does vary, so watch them closely.