Preheat the oven to 350 F. In a medium bowl, whisk together flour, pudding mix, salt, and baking soda. In a large bowl, mix together butter and sugar until fluffy. Add in the egg and vanilla extract until smooth.
Add in the flour mixture, and mix until it is fully combined. Divide the cookie dough between two bowls, and mix one with green food coloring and one with red.
Take a small amount of each cookie dough and roll together into balls. Place cookies onto a large ungreased baking sheet at least 2-inches apart. Bake for 10-12 minutes.
