European goldfinches in BBG native flora

July 4 around 6pm: Saw a pair in the north end of the open section of the new native flora garden (the one with the pool) close to the fence that abuts with the older, more forested section. They appeared to be feeding on tall fluffy purple / blue flowers (sorry not a botanist!). Naked eye, so did not see bands or other marks, but quite distinctive. They flew off south.