Okay, I get it now.
I have heard that Landseer's have a tougher time in the ring as well. That they aren't liked by judges as much as blacks. I really don't know if it's true, but if you look at dog shows, there are very few Landseers, and they hardly ever win. Chester, my brown boy, comes from many international champions, so I would guess the browns are better thought of by judges.
As far as the numbers of grays and browns, I'm sure there are far less grays than browns. On our BPO So. Cal. meet 'n greet, we actually saw a gray Newf at the restaurant where we had lunch. He was magnificent! Much longer fur than our blacks, Landseer, or brown. I've heard they have more skin problems than other Newfs.