They did, but I'm not sure if two-tone blue was one of them. The scheme I like the best (!) is the green frame, cream tank, and red wheels - I have a period reference for that. Some were black with cream tank, but beyond that I'm not sure.
The blue bike is one of the 1947-1950 models, but it has a feature that has me puzzled: the chain tensioner on the pedal chain near the back wheel. Some 1947-1950 models at least had an eccentric bracket for the pedal spindle, which was rotated to tension the pedal chain. (The same system was used on motorcycles from before 1910.) Can't imagine that you need both the eccentric spindle AND a chain tensioner, so presumably there was a changeover at some point. Beyond my pay grade...
I have visions of 33d6 in a medieval library (think Name of the Rose) poring over MS registration cards and musing over the revelations. I'm seriously excited.
Leon
[Edit: I should have said that I've seen the chain tensioner at the rear - like a derailleur - on other Malvern Stars, including some 1942-1946 models with the long tank.]