Preheat the oven to 350℉. Line 2 baking sheets with silicone baking mats or parchment paper.
In a large mixing bowl, combine the white cake mix, egg whites, and vegetable oil until all of the dry mix is moistened.
1 15..25 ounce White Cake Mix, 3 large Egg Whites, ⅓ cup Vegetable Oil
Separate the dough into three separate bowls. Set one aside for the white and add red food coloring to one bowl and blue to the other. Start with one or two drops and mix. Add more food coloring, one drop at a time, until you reach the desired color.
Red and Blue Food Coloring
Using a teaspoon size scoop, grab some of each color dough to fill the scoop and place 2 inches apart on the prepared baking sheet. Bake for 7-9 minutes until the edges and bottom of the cookies begin to brown. Remove them from the oven and let sit on the cookie sheet for 3 minutes before removing to a wire rack to cool completely.
Repeat with the remaining dough.