Prior to Bruce Horak's turn as an Andorian on Star Trek: Strange New Worlds, Star Trek had largely left the aliens behind after Star Trek: Enterprise's Shran, played by Jeffrey Combs. As it turns out, though. originally one Star Trek: Discovery character was going to be an Andorian. It was series creator Bryan Fuller's idea that got scrapped when he left the series in 2016 due to creative differences.
Anthony Rapp, who portrayed Lieutentant Paul Stamets on Discovery for the entirety of its five seasons, was originally cast as an Andorian. Fuller revealed the original plan for Rapp in an interview with The D-Con Chamber with Connor Trinneer and Dominic Keating [via Screenrant].
Either Fuller didn't know or didn't share why season one's showrunners Gretchen J. Berg and Aaron Harberts, who took over after he left, decided not to keep Stamets as an Andorian. It would have actually been interesting to see how Rapp would have played the character as, at the beginning of Discovery, Stamets was acerbic and more than a little snarky. Horak's Lt. Hemmer had the same kind of personality, and Combs' Shran wasn't really any friendlier. So, had Rapp played it the same way, we could ascertain that was the overall personality of the Andorians.
It was a shame when Hemmer was killed off Strange New Worlds as having an Andorian as a regular character on a series was unique, and had he stayed, we might have learned more about this alien race that always seemed to be suspicious. In the end, Hemmer proved to be filled with more heart than we'd ever seen in an Andorian when he sacrificed himself to save his friends and the crew of the Enterprise after he'd been infected by the Gorn's eggs.
Over the course of Discovery, Stamet's rough edges did smooth out, and he became one of the best characters on the series with heart, determination, and an indomitable spirit. It would have been great to have seen that with blue skin and antennae!