It depends on how wide the white bars on their feathers are. Basically, a single factor (one copy) barred rooster is darker, while a double factor (two copies) rooster is lighter. Hens can only have one copy of the barring gene, so if a hen is barred you know sheās pure for it.
Single factor black barred rooster (with some red leakage) [not my picture].
View attachment 2624285
Double factor black barred rooster.
View attachment 2624289
Barring on buff/red is a bit harder to determine. Actually, looking back at your pictures, rooster #2 could be pure for barring (meaning he has two copies of the gene).