Hard to tell for sure at this point (at least for me) but that comb looks like a single comb, and the feathers and legs look correct. So.... Until they fill out and tell us for sure, I would guess leghorn.
I have 6 White Leghorn hens would I be able to breed them with my a Welsummer Cockerel, if so how would they turn out? If anyone has any pictures that would be great!
Not positive but you might end up with a sex-link of some kind. If like the RIR to a White females will be redish color and males white. I know that when I did Barnevelder male on Columbian females they came out sex linked.