The reason is already clear to me, but I'm still curious to hear what y'all think about it-

[lilwanderer]

An RIR is pretty genetically similar to a light brahma, so that’s why you aren’t getting more variety in pattern. By looking at the offspring, it appears the father was probably gold, meaning that he would always produce silver/gold split (outwardly silver) male offspring and gold female offspring.

Do you have pictures of the other offspring?

The father wasn't exactly gold, he only had very few gold leakage, he was actually almost entirely black. I have one other from him that came from the same mother, but he looks very similar to other dark brahma look-a-like, just slimmer:

here he is

 

[lilwanderer]

Gold laced Sebright is gold.
Rhode Island Red is gold.
So as long as the Sebright parent was gold laced (not silver laced), your rooster is pure for the gold gene.

I see, what I'm getting out of that is that it doesn't matter what his feathers appear to be?

 

[NatJ]

I see, what I'm getting out of that is that it doesn't matter what his feathers appear to be?

Correct.
If he has the gold gene, he can give it to his chicks, even if he personally has so much black you can't really see it on him.

 

[lilwanderer]

Correct.
If he has the gold gene, he can give it to his chicks, even if he personally has so much black you can't really see it on him.

So almost always the hens will turn out gold and the males silver, that'll be helpful for the future.
Currently, i have a chick that came from that light brahma but the father this time is the son of the last one. He came from a barred rock and you already know what else, he looks like this:

Would it be about the same in his case?

 

[007Sean]

Howdy, Welcome to Backyard Chickens. Enjoy your time here!

 

[RoostersAreAwesome]

The father wasn't exactly gold, he only had very few gold leakage, he was actually almost entirely black. I have one other from him that came from the same mother, but he looks very similar to other dark brahma look-a-like, just slimmer:
View attachment 3054007
here he is

Every chicken is gold and/or silver, even if they’re solid black.

So almost always the hens will turn out gold and the males silver, that'll be helpful for the future.
Currently, i have a chick that came from that light brahma but the father this time is the son of the last one. He came from a barred rock and you already know what else, he looks like this:
View attachment 3054072
Would it be about the same in his case?

He’s a silver/gold split, so he’ll produce silver offspring and gold offspring (and silver/gold split sons).

 

[lilwanderer]

Every chicken is gold and/or silver, even if they’re solid black.

He’s a silver/gold split, so he’ll produce silver offspring and gold offspring (and silver/gold split sons).

would they be random this time or will they still be sexlinks?

 

[RoostersAreAwesome]

would they be random this time or will they still be sexlinks?

You need a pure gold (gold/gold) father over a silver (silver/-) mother to produce sexlinks, so they wouldn’t be sexlinked.

 

[lilwanderer]

You need a pure gold (gold/gold) father over a silver (silver/-) mother to produce sexlinks, so they wouldn’t be sexlink

You need a pure gold (gold/gold) father over a silver (silver/-) mother to produce sexlinks, so they wouldn’t be sexlinked.

Alright, noted. Now what if the mother were to be buff brahma related? Would the majority come out gold or?

 

[RoostersAreAwesome]

Alright, noted. Now what if the mother were to be buff brahma related? Would the majority come out gold or?

What do you mean by buff Brahma related? If the mother is gold, she cannot produce sexlinks, she can only do that if she’s silver.