In a mixing bowl, stir Elmer's glue and edible metallic paint. You can add more paint for extra metallic effects.
Gradually add Elmer's activator solution. The metallic slime unsticks from the sides of the bowl as you add more activator. Stop adding when the texture feels right, stretchy but not sticking too much to your fingers.
Store the slime in an airtight container at room temperature.
Notes
If you don't have Elmer's Solution to activate the slime, use some contact lens product that contains boric acid and add 1-2 tablespoons.If the slime is too sticky, it needs more activator. Add more contact lenses solution one tablespoon at a time.