I bet they’re pure!! Think you’d know if they were mixes haha sure they’d have red leakage.I have two Australorps left. I have 3 chicks who’s dad was an Australorp too but I don’t know if the mom was, I think she was but my Red Sex Links lay brown eggs too so I’ll never know.
The roosters my husband loves are a White Leghorn and Production Red. They are sweethearts. Mostly the WL.
And awww nice!! Mine are a Welsummer and a Lavender Orpington.