Union flag in Green and Gold.
http://cgi.ebay.co.uk/Union-Jack-Green-Gold-Badges-MGF-BRM-MG-TF-Mini-200-400-/390205317232?cmd=ViewItem&pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item5ada0ca070#ht_1067wt_1137
Tis OK. We weren't going to burn you at the stake
But seriously, no. In times gone by you could have ended up in prison for defacing the Union Flag.
It is also illegal to change the colours of brand names such as MG, but I can't imagine them taking an individual to court.