raptorific:

A new test for character design: “The Babs and Kara Test.” Your characters only pass if the audience could still tell them apart if they were wearing identical bathrobes and had their hair completely wrapped up in towels

Named for the time DCAU had Batgirl and Supergirl hang out in bathrobes with their hair up in a towel and needed to make sure their hair was slightly visible so the audience could tell which was which: