Seriously boss coat.
I think simpler is better with the rest of the rig too keep it from looking too costumey.
I like Pucci and think that jacket is pretty damn fun(ky).
Obviously it's only wearable for fun & informal occasions but within that, I think would look great with the usual rest of the dinner suit oufit. I do like the idea mentioned upthread of using a ruffled or pleated shirt with it, to complete the informalising effect. Normal dinner suit trousers & shoes though; nothing crazy needed there.