The photographs from the Cornell Lab of Ornithology are convincing, especially the third & fourth pictures of non-breeding plumage.

"White wingbars and white feather edgings on the tail contrast sharply with the black background. He is the only small yellow bird with black wings. The female wears less striking garb. Olive-green above and paler yellow below, she lacks the black cap and the bright yellow shoulder patches on her brownish black wings. Winter adults and immatures resemble females but are duller and more grayish, sometimes with only traces of the characteristic golden plumage."