Will I dont know of anyone local to you but I trust Lepsons in Swindon (theyre also in Kent) - they will refinish in
any colour though there will be a +charge for that I'm sure.
They did the wheels on my Pug and they will be doing the SAAB wheels with my summer tyres on when I get back from the Gulf in March April.
I asked for a strong glitter finish that they had shown me, for the Pug and I will be having the same finish for the SAAB. The colour is a brighter than standard SAAB silver, and has a larger 'metalflake' in it. In sunshine it really looks awesome.
http://www.lepsons.com/
EDIT:Thinking about it, they may even be familiar with the Hirsch finish, knowing Lepsons!