Clear faced females?

Hi! I've had two tiels that I was told were pearled males about 6 years ago. I thought one was sick so I put her in a quarantine cage and well.. Long story short, both birds ended up laying eggs. (Or maybe I didn't notice the egg at the bottom of the cage somehow before I split them up?) Both birds are practically identical, with the only differences being a few white and yellow speckles on the wings, and one having lighter claws than the other.
I was wondering what mutation could have caused this because I thought if a bird is split to pied it would change the feathers behind the crest rather than the face. They also seem lighter than normal greys but I don't think
there's any actual dilution in the feathers...


Here's the yellow speckles I was talking about, only because I'm not sure if they're normal