Not intending to insult anyone or their cattle, as I know everyone works hard at what they do and puts their heart into their cattle operations, so just more or less putting in typed words thoughts that I have on the various breeds as far as breeding for black hide.
I realize that some are now many generations from the original infusion of Angus and are now bred up to purebred status. It seems to me that right or wrong, good or bad, the physical appearance is altered so would not the genetic make up be altered as well.
My personal opinion from a marketing standpoint the Simmental breed benefitted perhaps the most. They are now a more moderate, and easier calving animal on average than before, and still retain the milking ability they were known for.
Perhaps Gelvieh have benefitted in growing their market acceptance as well for the same reasons.
Bear in mind I am not bashing any breed but I think it only worked for Limousins in that it gave them a black hided option, as I haven't seen very many black limousins that compared to the thickness and muscle of the original red ones, may be some are.
As for Herefords and Charolais, their respective associations don't recognize the black hided variants, in my mind they will potentially end up being very different genetically than the original breeds. I am not sure how well they will gain widespread acceptance as it would seem most folks who use them accept them for their trademark color as well the other reasons they are used.
It does seem that at least in this area there are some folks showing some interest in black herefords.