What color would the babies be?

[The Moonshiner]

They're both splash patterned mottled patterned, so the offspring will be the same as the parents mostly. You may get black, or blue offspring with mottling, it's also possible you might get split mottleds.

I'd take this advice with a grain of salt.
I'm not convinced they're splash but if they are two splash bred together would only give you more splash. No chance of two splash producing blue or black.
Also if they are both mottled all offspring would also be mottled. No split to mottled would be produced from two mottled parents.
I won't attempt to answer your question because their genetics are unknown so without knowing what all they carry it would be hard to give a correct answer.

 

[MysteryChicken]

So if I were to breed one of them with my blue oegb what might the colors be?

Splash is blue based which also comes from black. If you bred blue to splash you'd get half splash, some blues, blacks, & split to splashes.

 

[MysteryChicken]

This should make things easier.

Image from Internet.

 

[MysteryChicken]

Since yours has both red coloring, & mottling, you should expect some leakage in the offspring.

 

[The Moonshiner]

Splash is blue based which also comes from black. If you bred blue to splash you'd get half splash, some blues, blacks, & split to splashes.

Even with your diagram you can't get it right.
BBS breeding is very simple.
The blue gene dilutes black.
No copy of blue remains black.
One copy of blue dilutes black to blue.
Two copies of blue dilutes black twice which results in splash.
A splash bird has two copies of blue so when two splash are bred together both parents have no choice but to pass on a blue gene. That results in all chicks getting two genes resulting in splash chicks.
Your original post was incorrect as is this last post.
Blue bred to splash results in either splash or blue chicks. No chance for black and there isn't any such thing as "split to splash"
There is black, blue or splash. No split to anything with them.

 

[RoostersAreAwesome]

They're both splash patterned mottled patterned, so the offspring will be the same as the parents mostly. You may get black, or blue offspring with mottling, it's also possible you might get split mottleds.

They look more like dominant white red spangled (also called red shouldered). Are they oegbs? Seems like they're a project color. Or maybe just bad quality golden necks (dominant white mille fleur).
Red-shouldered yokohama (not my picture):

 

[RoostersAreAwesome]

View attachment 1937789 if these two reproduced what color might the offspring be?

Since they seem to be the same color, probably more chicks that look like them. But, if they are a project color, there might be some variation.

So if I were to breed one of them with my blue oegb what might the colors be?

Depends on whether they're mottled or spangled and whether they're splash or dominant white. If you breed one to a blue you should find out.

 

[RoostersAreAwesome]

Splash is blue based which also comes from black. If you bred blue to splash you'd get half splash, some blues, blacks, & split to splashes.

This should make things easier.View attachment 1937944 Image from Internet.

What you're saying doesn't correspond with the chart. You say blue x splash gets black and "splash split" (which don't exist). The chart says blue x splash can only make blue or splash.

 

[MysteryChicken]

They look more like dominant white red spangled (also called red shouldered). Are they oegbs? Seems like they're a project color. Or maybe just bad quality golden necks (dominant white mille fleur).
Red-shouldered yokohama (not my picture):
View attachment 1940028

You sure they're not a splash patterned mottled? They look similar to the dominate white red spangled, but blue based instead of white based.

 

[MysteryChicken]

What you're saying doesn't correspond with the chart. You say blue x splash gets black and "splash split" (which don't exist). The chart says blue x splash can only make blue or splash.

Blue would be split splash, cause splash needs two copies of blue to exist. Me saying splash splits is the same as saying blue.