If you only look at Willets when they are wading, you might not think too much of them. They are somewhat nondescript gray or mottled brown, and in the winter they have a smoother gray appearance. To my colorblind eyes, they appear not to have a splash of color on them. When I was new to birding, I was happy to check this species off as a new "lifer," but I didn't give them much of a second thought. Then one day I saw them flying. The outside of their wings are a deep black with a brilliant white stripe. This is even more apparent on the underside of their wings than on the tops of their wings.
If you're not familiar with observing birds, you may wonder how this could be. How could those feathers be so visible in flight, but invisible when the birds are standing? Let me venture a quick and simple answer if you're interested. Birds have three groupings of flight feathers. The outer feathers are called "primaries" and they fan out from the birds "hand." Inside the primaries are the secondaries, which come from the birds "forearm." And inside these are the "tertials." When a bird perches, the primaries fold up like a fan underneath the secondaries and tertials, which fold like a venetian blind. Since the teritals on top, they cover the primaries when the bird is perched, and if they are long enough, they may even cover the entire length of the primaries (or nearly all). If you look carefully at the photo above, you'll see a little black stripe at the end of the body. That's what's visible of those black and white feathers when the bird is wading. I hope that didn't bore you too much, but I think it's interesting.