I agree with KevG on this one. I borrowed this photo taken by Sonic_160zr, which I think is the right monogram colour we all had in mind and which I think is the real twilight on caled's post:
after increasing saturation +60:
Even though different cameras have slightly different hue/saturation I am sure that it cannot vary so much, surroundings are the proof... So, defo a respray, I've seen this colour on cars other than MG/Rover models...