In Texas it depends on the show. Ft Worth has some blacks winning, though last year it was the 2 smokes that took it and this yr they say he will use a Herf, Herf also won Georgia National this year I believe. At the slick shows down here, black isnt as dominating, for the past several years I feel like I have seen the smokes and reds winning it, but I think there may have been a black or two in there.
I think part of the issue with seeing so many blacks dominating is that the blacks did so well, that people are scared of color in a lot of places, and if they do get a really good colored one it ends up getting died black just to be safe. The smokes have been getting a piece of it in a lot of places for a while now, and I have seen some shorties get in there a few times. But as long as people keep dieing all the great ones black if they are colored, then yeah black will keep winning. If you want colored cattle in there then you not only have to have judges that will pick them, but you also have to have exhibitors that will give them a chance to win colored without dieing them.
The other reason that there are so many blacks and smokies, those are what fetch the premium at the sale barn, at least here in Texas if you take a colored one you are getting docked right off the top, so a lot of breeders still try to breed for one of the 2 colors, that way they dont get hammered on those that dont turn out and end up at the sale barn.