To be honest, I’m assuming these pictures are of a Pine Warbler. It could also be an American Goldfinch. I’ve gone back and forth in all my bird books and even checked out Greg Lavaty’s website (a real expert on birds), and I still can’t say for certain what kind of bird this is. If someone knows, please educate me.
Take this first photo. I “think” the bird in the foreground is the Pine Warbler and the bird in the background is an American Goldfinch.
In these next two shots, it really shows the beautiful color of this bird (whatever it is).
This is probably the same bird, but in the shot below, you can really see the beautiful brown eyes in addition to the yellow color.