Splash is just the homozygous or pure version of blue, so technically, not the same as Blue, but genetically pretty close if not almost the same. But it really is no different from Splash Wheaten, Splash Copper, Splash Duckwing, or any other Splash color except for the part that isn't Splash. Splash is just defining the fact that whatever the color is, it also has homozygous blue, AKA Splash. So if someone said Splash, they likely mean pure Splash, nothing else interfering. If they said Splash Wheaten, they mean Wheaten with the Splash gene. Same goes for Dun or Blue or Lavender. If it is just Dun, or just Blue, or just Lavender, it's that, nothing else. If it is Dun Wheaten, or Lavender Cuckoo, or Blue Copper, then it's Wheaten or Cuckoo or Copper but also with said other gene. That other gene is what affects the black color. Wheaten, Cuckoo, "Copper" (
also known better as Brown-Red) are the actual patterning. Doesn't matter if they're normal or if they also have Blue, White, Lavender, Dun, Splash, etc.
Did that make sense?
So "blue splash" Actually doesn't help define talking about pure solid BBS birds, since Blue and Splash are also found on any other bird carrying Blue or Splash. But just saying Splash or Blue, no other word, helps differ it from say Blue Cuckoo or Splash Cuckoo, because you never used the other word like Cuckoo. But if someone is in say a Wheaten/Blue Wheaten thread and only mentions "blue" they might mean Blue Wheaten.