Looks like a first winter bird. If so, the adult color should show up in the spring molt.

(link...)

Hairy woodeckers look almost exactly like downy woodpeckers, except bigger and with a longer bill. Sapsuckers act differently too. They sort of shuffle around on the tree, where the others are more active and move around more energetically.

Yes, that's got to be a first-year bird, and probably a female too. I've seen male sapsuckers this week with most of their breeding colors grown in.

To me, the easiest way to tell sapsuckers from downy or hairy woodpeckers is to look for the white stripes. Downy and hairy have prominent white stripes down the middle of their back, whereas sapsuckers have a white stripe on their sides and a black back.

The holes in the trunk of that tree (by the bark, it sure looks like a sugar maple) absolutely look like sapsucker work, too.

I think of yellow-bellies as being kind of dirty in appearance, kind of like a brindle dog. The black and white regions are not sharply separated but are more diffuse.