Bwalden, the pic of your rooster doesn't show his legs. It looks to me like your hen has white legs. Check her skin color. I have not found anything definitive on the subject yet but my guess is that the yellow gene is tied not only to leg color but to skin color as well. I've found that white legged Welsummers all have white skin too. So if the skin color on your hen is white too, you've probably lost all yellow genes in her and if your male has white legs too or is only carrying one copy of the yellow, you're gonna be in trouble for yellow legs. Remember, the yellow leg gene is not only recessive but sex-linked too. Look at the color of Bigtom's roosters legs. You can see some yellow in them but my guess is that both of them are only carrying one copy.
I bring this up not to put down anyone's birds but rather to emphasize that the yellow leg gene can be easily lost and I'm seeing more and more pictures of Welsummers with white legs.
Bjorn, nice to see you on here again. Hope you're doing well. Btw, don't know if you saw it or not but a few pages back I posted a few pics of my hen that took Champion Continental the week before last at Chehalis. I'd enjoy hearing your feedback on her.
God Bless,