This video from New York state in the USA says about itself:
American Goldfinches Begin Molting Into Winter Plumage – Sept. 21, 2018
The days of American Goldfinches‘ bright yellow breeding plumages are almost gone. In spring and summer, adult males are bright yellow with black foreheads, black wings with white markings, and white patches both above and beneath the tail. Adult females are duller yellow beneath, olive above. Come fall, the once colorful finches molt into their drab, unstreaked brown plumage, with blackish wings and two pale wingbars.
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