As I said, we have to look at the calendar when we're considering an unknown bird; for some reason, April 1 produces more than its share of weird reports.
All seriousness aside (as the saying goes), the molt really IS going on right now, and it's affecting the appearance of many birds. The American Goldfinch is a great example to watch because it may come to feeders right outside your window and because the change of color on the males is so striking. But a high percentage of our small songbirds are going through some kind of molt of their head and body feathers at this season, and with a close study, you may be able to see the contrast between the crisp new feathers and the slightly older, worn, faded feathers. It's a part of the survival strategy of the birds and it's something we can witness for ourselves with just a little extra attention.