On a walk this morning, we saw several bright yellow goldfinches feeding on the seed heads of a neighbor's coneflowers. These particular flowers are, I believe, a species of rudbeckia, which includes black-eyed susans. I don't know what attracted these gorgeous little finches to this patch, but the flowers are a light purple in color, with the signature rudbeckia downturned petals and large spherical seed head.
I don't know if the goldfinches are attracted to the type of flower or the specific color of this variety. They don't seem to feed on the black-eyed susans or daisies that I have in my yard, so I will be buying some of the purple rudbeckia and will make sure not to dead-head my flowers to allow them to go to seed and, hopefully, bring some more goldfinches to my yard.