Preheat the oven to 350 F. In a medium bowl, whisk together flour, salt, and baking soda. In a large bowl, combine butter with sugar until smooth. Add in the egg and vanilla extract and mix until smooth.
Add in the flour mixture, and mix until it is fully combined. Divide half of the cookie dough into another bowl. Mix the green food coloring into one bowl, and the blue food coloring into the other bowl.
Add 1/2 cup chocolate chips to each cookie dough. Take a small amount of each cookie dough, and roll together into a ball. Place the cookies onto a large ungreased baking sheet at least 2-inches apart. Bake for 10-12 minutes.
