Having had (and still have some bins) with pot worms, telling them from baby redworms is not hard. (Baby red worms do not stay white very long).
Look at what you are feeding your bin. Pot worms "bloom" when conditions in the bin become more acidic. If this is the case, you will notice, perhaps, your worms are not evident. The worms like conditions more neutral. As with all replications of natural environments, observation is key.

When baby redworms turn pink, are they still the same size as the pot worms, or are they bigger? Perhaps I'll just put some in a separate container and see if they turn pink...

All of my bins are currently pretty pH neutral - I know what you mean about a "bloom" of potworms becaue it happened once when one of my bins became anaerobic and many red worms died (I put uncooked, sprouted lentils in the bin. They must give off some kind of gas that killed the red worms???)...I had so many tiny white worms on the sides of the bin that you could barely see the sides of the bin! And all this time I thought they were baby red worms.....

Thanks!