[EBB Sightings] juncos

Relatively speaking, I am a rookie at this so I may be way off.  But we have had what appears to be a Canadian or Rocky Mountain
junco visiting our yard recently. Just one.   I don't know if this is even possible.  The bird looks in all respects like an
Oregon junco except the body is grey.  Has any one else seen a similar looking bird? This is a new sighting for us - for years we
have had Oregon juncos visiting, starting in the Fall.  This is the first sighting of the grey variety.  For reference purposes,
we live in the north Berkeley Hills.