This is nearly impossible to diagnose without more variables.
I agree it looked like it was being overwatered but that's hard to say for sure.
What soil are you using? What are you feeding and how often? ppm and ph? temperature and humidity in the room?
It could be yellowing from stress, ph is out of whack, over or underfeeding, climate is out of whack, overwatering,... could be a lot of causes.
If you are in a soiless mix you could likely fix the issues by first putting them in proper pots for God sakes... giving a feeding of straight water, followed by a feeding of 600ppm at 6.2-6.3ph, and dont water again until the pot is quite light, but not dry to the point of wilt. If you cant measure your feed rates, you need to fix that. Use a feed /feed /water schedule or feed /water /water.
If its organic soil.... Bennies tea. And again let it dry out but dont let it get too dry so that it wilts. Then you've gone too far lol.