There's an article on breeding blacks in the latest edition of Exhibition Poultry. If you click on the Aug 2012 link, it will take you to the PDF version. http://www.exhibitionpoultry.net/
You can also go back to the first couple pages of this thread. Breeding blacks isn't as simple as it seems. There are at least 5 different bases for it with different melanizers affecting each. I personally stay away from the black on blue matings because its hard to determine which offspring are black versus just a dark blue. The brown undertone is often seen with birds in need of a molt. The coal blacks are often just dark blues or poorly melanized blacks.
Thanks for your reply. I have actually read the article which has created more questions on my part. I find genetics very confusing for some reason. When seeking quality foundation stock, are there any specific questions I should ask breeders about their line?