Looking for some advice. I have had an altercation with a tow bar in a car park.

Very low speed impact, pushed in the front grill and scratched the paint back to the black plastic on the top of the bumper. Was wondering how i would go about getting some touch-up paint to fix the damage. The spot is roughly 1" square so I need paint that is a really close match or it will stick out like dogs balls. My car is Martini Grey Metallic (Gold Colour), paint code 703H. Does anybody have any suggestions on where I can source such a product.