BettaloverSara· Super Moderator
Stress stipes are not the only indication that a fish is stressed but that does look like a natural colour change. Were you able to get any more females? I am worried about the small one that you said was being picked on a little. Because they aren't fish that naturally live together it isn't quite the same as pecking order establishment. They will pick off the weakest and then fight it out themselves. I would add a ton more plants and add more females as soon as possible. That being said, I have never had a sorority myself so you can take what I have to say with a grain of salt.