What colour was Sir Harpo Newton's wig?

Harpo's rather sweet appearance in The Story of Mankind lends further weight to the suggestion that his 'blonde wig' may have been light red, as opposed to the preferred red wig he wore on stage (seen looking almost black in The Cocoanuts and photos of the Day at the Races stage try-outs).
Or is he just taking advantage of colour film to get the old red one out of the box again and it's photographed a bit lighter in colour than it looks in black and white? If you turn down the colour on this clip, it could pass for the 'blonde' wig, familiar from the majority of the movies.
Or it could be a third wig, did you think of that?
On the other hand, the almost glowingly blonde one he seems to be wearing in fifties TV appearances (and A Night In Casablanca, but we can save that argument for another day) really is blonde, isn't it?
So that's four wigs. Do I hear five?