As far as the color thing goes, it may appear that black cattle win because they're black...I very seriously doubt that's the case. A lot of people who show steers prefer black hided cattle, and I think there are multiple reasons. Black cattle are easier to fit because flaws don't show up as easily. Any type of flaws--both structural flaws that are part of the calf's design AND errors made in grooming & fitting--sometimes show up less on black cattle. There is a perception, sometimes valid & sometimes not, that black cattle may have better carcass traits. Black cattle stand out in a show ring against a backdrop of multiple colors. And it may just be personal preference... Most judges are looking for the most complete & industry oriented steer, and often, the kids who are most serious about competing, buy or raise the better calves, and know how to feed & fit them, are showing black calves. Plus crossbred calves (and crossbred could include multiple breeds here) are usually the most suited for county fair type shows, and those calves often come wrapped in a black hide. The SimAngus is a good cross, and if you find the right mating & do a good job feeding & fitting, they're just good cattle. Herefords, in general--and at least in my part of the world--aren't known for muscling & thickness, and most of them can't compete with thicker, fancier crossbred calves.
Most of us have a breed preference, but you can't blame a judge for a breed's shortcomings in a market steer show where breeds compete against other breeds. I think a lot of folks now are looking for colored up calves in order to stand out in a sea of black cattle, but you still have to have the traits that matter...muscling, finish, style & balance & soundness...if you want to be competitive. If you like the Hereford color pattern, try to find a crossbred calf that has that coloring & APPEARS to be straight Hereford...you CAN make those! Or show in shows that divide by breed so you don't have to compete against other breeds.
The point of showing is to merchandise our cattle and to learn about the industry from judges and other breeders. Try to understand why cattle win, and look past the color of their hide. I would bet if you could peel the hides off, you would be able to see the real reasons most of em get sorted the way they do.