Hi there.
As far as I know... black, blue, and splash are NOT sex linked in any species and certainly not ducks.
If you breed a black Swedish drake to blue Swedish hens... you should get 50% each black and 50% blue. If you breed two blue Swedish... you get approximately 50% blue, 25% black, 25% splash... but that has NO indicator of gender.
If you want sex linked ducklings... use a chocolate drake over any other colored hen and all chocolate offspring will be female with others being male. Noting that if using a chocolate male over blue hens... the female offspring may be lavender instead.. and telling down colors apart may be difficult without practice. And white can be hiding other things so not ideal for using in this instance. Refer to that article though, for more information if needed as it was a good source of basic information.
I do remember Rouen ducklings being auto sexing by bill color at hatch, but quickly becomes the same until maturity. Since then, most information has been removed from the web, like it's a big secret.
The simple answer you were looking for on the other page is NO, your mating in question will NOT produce sex linked ducklings or any splash. Just black and blue.. of both genders.
Hope this helps!
