I’m glad you clarified that I’ve been sitting here looking online trying to figure out how to create a splash old English game and could not figure it out. I was guessing that it would’ve been a blue with a white but obviously I was wrong, so thank you for explaining that blue on blue can produce splash.I'll break it down as simply as possible. Splash birds have two copies of the Blue dilute gene. Blues have a single copy. Blacks have no dilute gene at all.
So Splash to Splash produces only Splash offspring. Blue to Splash will produce 50% Splash and 50% Blue. Blue to Blue will give you 50% Blue, 25% Splash, and 25% Black. Blue to Black will give you 50% Blue and 50% black. Splash to Black is the only pairing that will give you 100% Blue.