When we went to try on the dresses back in August, the other bridesmaids claimed their dresses—hot pink, canary yellow and neon orange—before I could say boo, and all that was left was aqua.

Eyrich’s team ordered aqua bridesmaids dresses from Los Angeles-based Jenny Yoo (who also did the girls’ dresses for Kurt and Finn’s parents’ wedding) on a Wednesday; Yoo made them on a ...