ok - in that case you do not have a cooling off period.
Its a hard one, but sadly I dont think you have a claim or can get it changed. However I will outline the process if you want to claim the cost of the wrap in any event.
You signed the order at BMW and this means you dont get a cooling off period - you do on the lease but not on the order itself.
You signed the order as Midnight Grey. You could have looked at this online, which you did later or gone to other dealers to satisfy yourself as to the colour. You ordered and got Midnight Grey. Just because it is not the shade you want it is for the reasons above I dont think you have a claim.
However at best, ***** ***** try and get the £950 for the cost of the wrap.
You need to write and set out your losses and request they do the wrap for free or the £950 to get it done within 14 days or say you will go to Court within 14 days. You should make sure you send this signed delivery and keep a copy.
If they do neither you then you can issue proceedings in the County Court. You can either do this online at: www.moneyclaim.gov.uk or by completing form N1 http://s3-eu-west-1.amazonaws.com/hmctsformfinder/n1-eng.pdf and take it to your local County Court.
The Court will then issue a claim which a copy will be sent to the Defendant who will have a limited time to defend it, if not you can enter Judgment and enforce.
If the claim is for £10,000 or less it will be a small claim so you will not need legal representation. Over this value you would need representation for trial.
I am sorry if this is not necessarily the answer you want and certainly not the one I want to give you, but I have a duty to be honest.
Can I clarify anything for you about this today please?