Back on July 18, my brother Mike came over to shoot pool - I LOVE shooting pool and have a table in the basement - and I was showing him all the action in the Partridge-pea. He peered into the plants and spotted the grasshopper, sitting just as it is on the fruit of Wild Blue Indigo (Baptisia australis). Fortunately, my macro rig with flash and diffuser was sitting inside on the kitchen counter. I did not pose the grasshopper, although I confess the bug looks good on the fruit. I'm not saying I wouldn't have perhaps posed it there, but you try "posing" a grasshopper sometime. Not easy to impossible.
Anyway, orthopterans routinely but rarely have pink or yellow variations, but I've never seen nor heard of yellow forms with this species. A bit of a scan around the Internet for images produced only one or two, so I imagine lemony-colored Differential Grasshoppers are pretty rare.