When you're dealing with black/blue/splash, you just have to keep the pattern genes straight. For instance, don't be breeding a splash wheaten to a blue copper, or a "plain" splash to a black copper. Other than that, you're pretty much good to go.
Ideally, if you breed blue in any of the patterns (based on any of the E series genes -- E=extended black, ER=birchen or black copper depending on other genes, EWh=wheaten), you should work for a dark blue with good dark borders on the blue feathers. But that is soooooooo far down my list of things to worry about.......
In general, feel free to breed blue, black, or splash together AS LONG AS they have the same "E" alleles. That's why a lot of people (check my sig file) say they breed "blue/black/splash" or "BBS".
Ideally, if you breed blue in any of the patterns (based on any of the E series genes -- E=extended black, ER=birchen or black copper depending on other genes, EWh=wheaten), you should work for a dark blue with good dark borders on the blue feathers. But that is soooooooo far down my list of things to worry about.......
In general, feel free to breed blue, black, or splash together AS LONG AS they have the same "E" alleles. That's why a lot of people (check my sig file) say they breed "blue/black/splash" or "BBS".