I wouldnt even try and match them yourself, and i wouldnt rattle can them as the finish will be leaps and bounds worse than the wheels probably. Go to a professional paint place, get them to match the colour, send us the paint in a wee tin with the center caps and we'll do them for you for not alot of £.
Failing all that, and having ALOT less bother, id get the wheels wet sprayed.
Cheers,
Si