ABC Movie shot at the beach with girl with shoulder-length purple hair

So, I was at the beach over the summer (Torrance Beach in Los Angeles, California. I can't post links, but it was basically exactly at latitude 33.812973, longitude -118.391726), and ABC was filming a movie (there's a small chance it might have been a TV show). I don't remember exactly when this was, but it was some time around July 2017. It was a big production with lots and lots of crew members, and they had probably around seven or eight or more trailers with them.

Anyways, here's what I remember:

This was shot by ABC (or an ABC-owend production company — they had a sign and among all the legal stuff it said ABC on it) at day time on the sand about 60 yards from the ocean, and you'd be able to see the ocean and the sky in the background. The main character of the scene was a white girl, probably around 17 - 22 years old with close to shoulder-length purple hair (it might have been a little longer or shorter). I think she was wearing all black, but I can't completely remember.

Also, there's some stuff I noticed about the background of the scene, which I'm not sure made it into the final cut. There were around five extras standing around in the background holding surf boards. Also, at one point two women, one with a bright red-orange swim suit, would walk down the beach from where the camera was to the ocean.

At first I thought it was Descendants 2, but I looked and couldn't find any scenes like that.

If you need anything else to help me figure out what they were shooting, I'll see if I can remember. Thanks so much!