That black rooster is stunning!
Leakage is the base color showing through. My first Ameraucana rooster had bleed through base color, which he did pass on to his male offspring-it can show on the females, but rarely do you notice it on them.
He had one son with such severe bleed through that it was almost silver.
My rooster-the black hen I posted above is his daughter. You can see the color showing through that should not in hackles, wings and around the comb.
View attachment 1167458
View attachment 1167468
The son of his that shows why you don't usually breed a bird with this leakage/bleed-through color:
View attachment 1167462