Speckled Sussex?

[Massey83]

Hi. I have 2 chicks that are supposed to be speckled sussex, but at 3.5 weeks of age, I'm not fully sure that's what they are. They looked correct as day-olds (I think), but they're getting feathered legs which doesn't seem correct, and I'm not sure about the colouring either. Pictures are attached. Anyone with experience raising them that could offer some feedback?

Thanks

 

[RoostersAreAwesome]

Buff Brahmas

 

[rosemarythyme]

Definitely not SS, as they should be feathering in with the speckles, and of course they wouldn't have feathered legs. Not sure what these are.