www.Paintnuts.co.uk were fantastic in getting me a "volcano Orange" touch up stick, I tried many including the bigger names who had this as the default answer, these guys did some research off their own back & found the EU colour "fizzy Orange" as it's called and made me one up which is the exact same, why they change the colour names for diff markets I don't know but I really couldn't praise them enough.
Im staggered at how clueless some dealers & mainly MG UK head office are about reasonable, you'd think quite common Q's, after ringing them once about a warranty issue on my old 5, that was comical but that's another story..... I've used a few touch up sticks in the past with awful colour match and the nib dries up etc. I've used this a few times now when I see one & it's fresh every time & a great match, was less than £15 I think too.