Could never understand why they were called Coltwood when they were made of plastic and not wood. Not an expert on those models but have seen Coltwood stocks on the Pocket Positive and New Police. I've seen black hard rubber, checkered walnut and smooth walnut on a PP.
Real "Coltwood" stocks were only used for a limited time during the early post-war period from 1947 to 1953 or so. "Coltwood" was the trade name Colt used to describe the plastic grips made by their plastics division. The early grips were reddish-brown with lots of swirling, the later grips showed a more uniform dark brown color with less evident swirling.
To answer the question, the Police Positive was never furnished with Coltwood grips. The Police Positive model was discontinued after WWll and was replaced by the Police Positive Special which combined both 32 and 38 calibers in one model.
Here is an early post-war Police Positive Special with Coltwood grips.