[Lorraine]

I have no idea wher eyou get the idea of hatred. Colour in the YOrkie is about the breed standard handed down over a century ago now from the breeders that developed the breed, had it recognized and along the way the colour was defined with other colours not being acceptable.
All purebreds recognized by bona fide registries such as AKC in the US and CKC in Canada, have a breed standard. It always defines size in some form, some include colour and in some it has to be certain colour patterns depending on the breed you are talking about. That is what a breed standard is for.
The Yorkie show fanciers don't hate the Biewers or parti colour. Go ahead and put in the work, money time etc that purebred fanciers have put in to have their breed recognized, and have parti's or Biewers recognized as a purebred but they are not a yorkshire terrier.
Chocolates and blue born are yorkshire Terriers as a result of recessive genes. Never a good idea to breed for recessive genes. Health issues are usually carried along with them. They certainly are registerable with bona fide registries as Yorkshire Terriers but no reputable breeder would ever purposely breed for them. BEcause it is against the breed standard and breeding purposely for wrong colour is not breeding with the breed standard in mind. This is going to be the case with any purebred breed you are talking about.