Sorry to hear your bad luck doing your wheels and I'd forget the place you bought it from tbh. Just write a letter to the Halfords head office here in the UK. You will probably get nowhere though but it's definately worth a try imo.
I've sent complaint letters to; Benson & Hedges, Cadburys, Nestle, Rizla and they all replied, compensating me in a fair way for faulty products. ...But a fire works company did not compensate me at all after one of there fireworks designed to go off in the air went off at ground level and that was bl**dy dangerous. Some companies will just ignore your crys unfortunately.
Also the problem is a lot of manufacturers in all industries when dealing with coloured products do whats called "batched lots". These lot's will all be the same colour but due to things beyond there control there will be colour shade differences from batch to batch (eg; batch number 201 black will not be the exact same shade as batch number 202 black etc even though they're both black).
My girlfriend does knitting and if shes doing a large piece she has to ensure that all the wool yarns have the same batch number/code on the label in order for the colour to match. It's the same with auto paints too unfortunately and probably rife in somewhere like Halfords where it's done on a large scale.
What I'd do if I was you to sort your wheels is go to a proper paint shop and get them to make you up 5 spray cans of the colour you want. This way you will be assured that each can contains exactly the same shade of colour. They can also make you a touch up paint pen aswell and supply you with anything else painting related you will need.
I use my local place (Autopaints, Ely, Cardiff) but unfortunately it's probably too far for you to use.
Maybe try a google maps search for local auto paints shops in your area. :salut: Hope that helps abit and good luck [smilie=karls_thumb.gif]