The little Lesser Goldfinch is such a pretty thing. I believe this bird is a female. The problem with the Goldfinch is that they are so active, seldom staying still for long. They say that they come to feeders, but I haven't seen any yet. This one taking flight was seen at Delta Ponds.

Coloration

"Males are bright yellow below with a glossy black cap and white patches in the wings; their backs can be glossy black or dull green (particularly on the West Coast). They have a black tail with large, white corners. Females and immatures have olive backs, dull yellow underparts, and black wings marked by two whitish wingbars." (Quoted from 'Allaboutbirds.com' -
https://www.allaboutbirds.org/guide/Lesser_Goldfinch/id