Quote Originally Posted by Bonny
Make sure the parents are not both Blu Merles. That is a no no in breeding Aussies. Also make sure your pup has a dark colored nose. Sometimes they have the pink nose & that can get sunburned & sore. A solid colored black or brown nose is best.
Great points but actually any merle should not be bred to any other merle, not just blues.

A dark colored (black or brown) nose is just as good as a liver colored nose (can be light brown), but yes, pink pigment on the nose or eyes is not that good, like you said they can be prone to sunburn.