Almost every example I have seen is either red or black in the '40s. Late '30s WLDRs seem to show up in the '39 two-tone combo, really nice looking. My '50WR sales brochure lists Brilliant Black, Ruby Red, and Riviera Blue as standard with Metallic Green, Flight Red, Azure Blue, and White as extra cost options.
And as far as "Race Team", there was none. The riders were sponsored by Dealers or were privateers. H-D did not field a team per se. So if a dealer wanted their own colors they painted them! H-Ds involvement usually only went as far as offering replacement parts at cost. There was no travel allowance or wages. If the racers were lucky they got to keep all of their winnings. In some cases the sponsoring dealer got part of it!