I'm not sure I would call it 'colour discrimination', but what you are describing is just a fact of life. Life is unfair and the showring is even more unfair. I have been to a royal show where I took a team of 15 shorthorn and shorthorn cross steers and not one of them placed on the hoof. Out of 128 steers on the day, not one shorthorn steer was placed in the top 10 of a class. However, when the carcase results came back, every one of my steers won a ribbon.
This year at sydney, belted galloways did extremely well in the carcase competition, being only a few points away from the angus steers. But no one would ever place a beltie on the hoof, and there are only a few brave souls who would feed them out for show (myself excluded - I also thought they were not much more than a hobby breed, but I was wrong - those results were eye opening).
We get the same thing in interbreed competitions here with our murray greys, not so much a 'colour discrimination' but a 'breed discrimination'. Almost every interbreed winner at royal shows here is angus-charolais-shorthorn. There is not a lot of allowance for other breeds. Showing square meaters last year in the interbreed, the judge said and I quote "Today I am looking for an animal which can fit all the markets in australia, breeds like the angus, shorthorn, charolais and to a lesser extent limousin. For this reason I will not be looking at the small breeds, such as lowlines and square meaters, as there is not much point". Yet the competition outlines state that the class is for the animal which best represents its breed.
Square meaters are not supposed to fit all the markets, they were developed specifically to fit a niche market - the milk fed vealer.
As I said, it is just a fact of the showring that often black hided animals are placed over just as good or superior coloured animals. The way I see it, you have three options:
a)if you dont like it, go and show black cattle
b)show your red/white/yellow etc cattle but whinge and complain about the unfairness of it all
c)show your red/white/yellow etc cattle and consistently put out better and better animals until they have no choice but to take notice of you.
That last one has worked well for us the past few years. You have to put out animals far far better than you would if they were black, but thats just the way it is.
I will get off my soap box now.