It was possibly interdimensional or alternate timeline travel not actual time travel
In one episode they traveled to a society that had assigned everyone numbers instead of names and they wore helmets with their number on it, so you couldn't see their face. 2 people had fallen in love and this was not allowed. I think the explanation was to keep people from judging people on their looks. This might have just been part of an episode and this was just the closing scene.
Possibly the same show - Robots are slaves to humans and gain freedom. Last scene woman with bright colored hair and spring shaped bun on top of head, allows robot to play with bun.
I'm pretty sure it was a US TV show and the actors were mostly teens/preteens.
I don't think it was "Ark II" but it had a similar look.