What notable change occurs to the Goldfinch's non-feathered parts between winter and breeding season?

Answer

The bill and legs shift from a dark grayish-brown to a buffy yellow-orange color

In winter plumage, the legs, feet, and bill are dark grayish-brown, but these features change to a buffy yellow-orange color by the time the breeding season arrives.

What notable change occurs to the Goldfinch's non-feathered parts between winter and breeding season?
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