RIR or Isa Brown

[chicksinthemachine]

How do you tell the difference, they are about 3 months old and not sure, I thought they were Isa Browns but my husband thinks they are RIR's, I can't tell the difference.

 

[chicksinthemachine]

Well I was doing a little bit more reading and discovered my own answer. RIR typically don't have white on their feathers and mine do.