I went ahead and bought another blush pink dye, applied it, and it is still gray. :(
Amary is wondering if the background of your crest stamp is gray. If it's gray, it may be forcing that color over the rest of the outfit (hence why it would first load in pink, and then load gray once the UCC catches up). If it is, she suggests putting a new UCC stamp on the costume without selecting a background color in the UCC stamp maker. That may lead to it staying pink.