I think it has a branch "sporting" which is when bud(s) mutate and produce variegation from the new-growth. It very well could be that it started sporting some time ago and you were lucky to have it sold to you. I've never seen a Cotinus with those colors.

Now here's the deal, since it's such a nice sport, it should be propagated to save it. My friend in Canada at 'Whistling Gardens' Darren Heimbecker is someone that would be able to help you to accomplish this. It's imperative that the propagation is done just in case the leaves revert back to normal. I'll notify Darren to have him take a look at this thread.

If it is a cultivar I have never seen... so be it. Otherwise a superb find and possible introduction to future gardening.

Best Regards,

Dax

This margin coloration is pretty common to see on Cotinus RP in the PNW, not sure what causes it. Not seen on new growth,shows up normally after growth has stopped or terminal bud has set on a given branch.

Schmoo

Yep.