Color is another red flag issue. If the breeder is breeding “for Color” or getting rare for the breed color on a regular basis you run a big risk of having other inherited issues. Some issues are physical while other are psychological. This can be said for any main points of written standard.
As the buyer you will need to decide which issues are important to you. I think one of the best questions to ask a breeder is “ How long do your dogs live?” If a dog is passing on at or after 12 years old I do not feel the exact reason is of much importance. On the other hand if a fair number is passing at 8 or less then again it may not matter why, they are still passing way to young.
Proof is in the pudding. If you are buying a hunting dog and the breeders have a suggested that they have “great hunting dogs” are there pictures of the parents hunting or after the hunt. Do they have pictures of more than 1 generation of their dogs hunting. If you can hunt with the breeder and their dogs, or watch them at a field test that is even better. Hunt test at least so the dogs have the basics for hunting.
Where are the pups whelped and raised the living area of the house or outside. The best is in or close to the living area of the house. They should be bot whelped and raised as close to normal human activity as possible. Each breeder has a different house and setup to deal with. Personally I keep the whelping area off to the side but the pups are near and exposed to normal goings on in the house, vacuums, other dogs, phones, and people. Some breeders will whelp the litter in a separate area then when weaned move them further outside. Then claim they are housed raised. It is necessary to be specific when you ask where and how the pups are whelped and raised.
If weather permits has the breeder taken the pups outside.
As you can see picking a breed may be fairly easy but picking a breeder is the hardest part. This is not a complete list of questions or a complete list of issues and concerns. Hopefully thought it will give you a general idea of what to ask and what kind of response indicates good and poor breeders.
The breeder that you pick should be someone that you can work with throughout the life of your dog.