To get the color of the rooster you have, Id guess that the Cuckoo Maran in his parentage had a dominant black gene and a recessive something else with the rooster getting the recessive something else, so all my calculations below are probably wrong to start with. However, it was fun to run the calculations. Im no expert by far so if any of the ones that actually know what they are talking about on this subject see a blatant error, Ill not argue with you. Ill just pay attention and try to learn.
Ignoring the incompletes and clearnecked, which I dont understand plus it greatly shortens the list, the possible results I come up with assuming a Cuckoo Maran rooster and Buff Orpington hen parentage on the rooster crossed with a Speckled Sussex hen are:
Black Patterned Buff Columbian Barred,
Black Patterned Buff Columbian,
Black Patterned Red Columbian Barred,
Black Patterned Red Columbian,
Black Patterned Redshouldered/Cream Columbian Barred,
Black Patterned Redshouldered/Cream Columbian,
Black Patterned Silver Columbian Barred,
Black Patterned Silver Columbian,
Black Unicolored Barred,
Black Unicolored for the female and
Black Patterned Buff Columbian Barred,
Black Patterned Buff Columbian,
Black Patterned Yellow/Gold Columbian Barred,
Black Patterned Yellow/Gold Columbian,
Black Patterned Red Columbian Barred,
Black Patterned Red Columbian,
Black Unicolored Barred,
Black Unicolored for the male.
I imagine this could change some if the roosters parentage is Buff Orpington rooster and Cuckoo Maran hen instead of the other way around but I had to assume something. I also know that there is a real chance of recessive genes showing up in any of the parents that are not accounted for in this and that there are different ways to make Buff. This also does not account for any leakage or the effects of any melanizers. With the actual rooster being the color he is instead of the black barred predicted by the calculator, Id suspect diluters, leakage, and melanizers at work, or maybe the Columbian gene doing something, or most likely a recessive gene in the parentage, which means the results could be even more unpredictable than the above list. And the plumage shown in the photo is Juvenile plumage. There could be some differences in the final adult plumage.
Now, assuming a Buff Orp rooster and a Cuckoo Maran hen for the roosters parentage and a Red rooster and Barred Cuckoo hen for the parentage on the Black Sex Link, (many different ways to make a Black Sex link but I have to use something) the possibilities I get are:
Black Patterned Buff Columbian Barred,
Black Patterned Buff Columbian,
Black Patterned Buff Wheaten Barred,
Black Patterned Buff Wheaten,
Black Patterned Lemon/Cream Columbian Barred,
Black Patterned Lemon/Cream Columbian,
Black Patterned Lemon/Cream Wheaton Barred,
Black Patterned Lemon/Cream Wheaton,
Black Patterned Gold Columbian Barred,
Black Patterned Gold Columbian,
Black Patterned Gold Wheaton Barred,
Black Patterned Gold Wheaton,
Black Patterned Red Columbian Barred,
Black Patterned Red Columbian,
Black Patterned Red Wheaton Barred,
Black Patterned Red Wheaton,
Black Unicolor Barred,
And Black Unicolor for both the pullets and cockerels of this mix.
You can probably tell it is mixed rain and snow outside and I dont have a lot to do inside this morning, plus I have fun with this. That calculator can be addicting. But once you introduce even one mutt to the breeding mix, the possibilities of what the offspring will look like go way up. Then you throw in the recessive genes, especially from the hatchery chicks, and you really dont know what you will get. Add to the unknowns that there are different ways to genetically make a lot of the different colors and you add to the confusion. Add in diluters, melanizers, the effects of Columbian, and bleeding. I like mutts. You never really know what you will get when you cross them.