I'm hoping some of the bird ID experts can help me with a little bird that I saw at the feeders today.  It was about the same size as a Downy Woodpecker but plumper.  The bill was black and thin.  It had a slate black head and back and a ruddy collar and upper chest.  The "tummy" was a buffy color.  It looked like a bluebird except it wasn't blue.  The day was overcast and I wondered if the lack of sunlight could explain the lack of blue color.  Could this be a female bluebird in her winter clothing?  Thanks in advance for any help with the ID. 
Vanda

 
Happy Birthday, Mirta!!!
Vanda