Stir in your coloring- either food coloring or if you can find glow in the park washable paint in a craft store that would be fun too. Just add a few drops according to how vibrant the color you want.
In a separate bowl, mix 2 teaspoons Borax and ⅓ cup warm water. Stir until dissolved.
Mix both bowls together and you have slime!!
Recipe by My Frugal Adventures at https://myfrugaladventures.com/2012/10/childrens-craft-idea-how-to-make-green-slime/