This butterfly reminds me of a lady going to tea in a lemon coloured chiffon dress. They flit very nonchalantly from bloom to bloom, seldom alighting for long. They must know that they look extraordinarily beautiful against the hot pink of Sedum blooms, as that seems to be their favorite haunts. Their wings are almost transparent, adding to their fragile appearance.
Although not around in great numbers, there are usually a few around for the most part of the summer. Their diet is quite varied, so with a butterfly garden of plants to choose from, they'll quite happily be the belle of the ball.
This one seems to be sometimes listed as Cloudless Giant Sulphur, so I'm not sure if they are two different ones, or the same.