Welcome to the Forum!
I do know a LITTLE about the 22 semi-autos. (Enough to be dangerous.) But I seem to recall a version, in limited quantities where the gun was a two-toned variation.
However,, it will take a bit of work to figure out if your gun was shipped as a two-toned one. Did you get the box with it? If so, what is the model info on the end label? (Example; KMKII-514) If you didn't get the box, you would need to get that info from Ruger. They are in the process of a few changes in the Records division, so it may take a bit to get that info. Ruger will want the model, (MKII) and the serial number. They can tell you how it was built & shipped.
However,,, due to the MANY aftermarket upper receiver sales, (Pac-Lite) we are seeing a LOT of miss-matched guns appear.
I bought a pair myself last year at an auction. Cheap too!
Maybe our member, 1gunsnotenough will see this thread & comment. He collects the MKII's.