Grey, Black, they made both. The snap-in vs. screw-on switches is the giveaway. I can't say for sure that nobody ever made knock-offs with snap-in switches, but I've never seen any.
Also, I once saw a stick with screw on switches that I think was true Wico- it was the stick they made as a replacement for the optical stick that came with Berzerk. I would have thought the seller was full of it, but he had the installation instruction sheet, said Wico right on it, and appeared to picture the same stick in the auction. It had the screw on switches. Maybe that's where the knock-off makers got the mold for theirs? At any rate, you probably won't see any Berzerk replacements for sale cheap, so generally you can assume that if it's got screw-on switches, it's a knock off.