There are a lot of varieties you don\'t want to cross, but Black, Blue and Splash are different. Do you already know about the Blue gene?...the Andalusian gene?
Unless you want to breed only black, the Splash or Blue boys crossed with your Black hens would give you these different colors, so a lot of people keep these penned together.
black x black = all black offspring
black x blue = 50% black, 50% blue
black x splash = 100% blue
blue x blue = 25% black, 50% blue, 25% splash
blue x splash = 50% blue, 50% splash
splash x splash = 100% splash