Good luck on that, I've got the silver grey GT line wheels been looking for 12 months now, no chance, seems Renault do not have paint codes for wheels, Wheel Smart did a colour match, Mmmm not good at all once finished. you just can't get the shade right once dry. you may end up painting two on the same side front/rear to match. I did this in the end.
I am afraid you have set yourself a task which sadly I doubt you will complete, sorry for the bad news.
I did come across a site earlier this year you claim to be able to match my colour calling it GT Grey or something like that, but they wanted £36 per half Ltr plus post just for the base coat, you then need high gloss lacquer on top for another 30 odd quid, ok I thought, but they then went to a disclaimer about how different spray pressures, coat thickness, temp etc all will change the colour of the finish, even down to the primer used but they did say what colour primer to use either, so I am going to spend in the region of 80 odd pounds getting this paint to me with no quarentee its the right colour anyway no matter what I do. So basically it's the right colour but might not be.
Sorry again for the bad news.