Ensure the paint is safe to use both on your skin, and on your dog. Because it will get everywhere! The way this works is you get a big canvas, safe to use paint, and then do whatever you want. Use your hands to smear paint on the canvas, do little drops of paint and have your pet walk across, or roll over on it. And to clean up, pull out the hose in the yard and let your dog bite at the water!
There's no one more artistic than Wes Anderson. And if your dog is artistic, then any of Anderson's films will do just fine. May we suggest Isle of Dogs? Just remember, get some healthy snacks for your dog to much on throughout. It's not like you're sharing your chocolate, that would be a bad idea.