It does not matter which parent is black and which is splash. You could even set up one flock each way, depending on how many you have of each color.
It does matter that the "black" is a Black Laced Red and the "splash" is a Splash Laced Red (not solid black, not splash all over.) This is probably obvious to you, but I'm stating it just to be sure.
Is it important to you to get 100% blue offspring? Because otherwise you can breed blue to blue, or blue or black, or blue to splash. Each of those will give 50% blue offspring, along with various numbers of black and splash.
You could have a flock with a blue rooster, and hens of all three colors, and you would get 50% blue chicks from all possible combinations.