Battle of Britain Film Spitfire Question

I know that the markings on the Battle of Britain film Spitfire were in some respects not the most accurate.

I seem to remember reading that the roundals and fin flash were brighter colours than the wartime specifications. Was it really that noticable a differance. Seems hard to tell after looking at so many pictures due to tonal variations of the film.

Can anybody comment further on this ? Trying to get the tones right for a forthcoming decal sheet I am to retail.