Ok, I give up. Is it a warbler? Is it a vireo? Is it a Goldfinch that had beakoplasty?
The Wilson's Warbler that toodled through the same trees a few minutes later was so much easier to id!
The lighting was extremely poor and the bird was very far away from me, so it's quite possible the camera is registering colours incorrectly. E.g. it may be less yellow than this etc.
[attachment=0:1umwn7bc]WarbVire3.jpg[/attachment:1umwn7bc]
[attachment=1:1umwn7bc]WarbVire2.jpg[/attachment:1umwn7bc]
[attachment=2:1umwn7bc]WarbVire1.jpg[/attachment:1umwn7bc]