The fluid sac around each kitten generally has light amber fluid. If the mother is in labor, she should have contractions coming on a regular basis. Sometimes you see them pushing or straining. Generally we want a kitten to show after pushing, but not to let her push for more than two hours. Cats are able to stop their labor, so I would try to observe only and not get involved. Cats have little trouble with delivery and don't require our human help, sometimes much to our dismay. The darker yellow fluid may have been a combination of urine and the bag of waters.
If the kitty is pushing hard and not delivering a kitten within two hours, then you need to call a vet. They can fatigue and sometimes need help with some injectible pitocin to complete delivery.
I hope this is helpful. Please push ACCEPT and good luck!
All I hear you describing is possibly a cat in advancing pregnancy. The restart their labor generally within 72 hours. If you continue having this much concern, you need to take her to your vet.
Again, once she begins hard contractions, a kitten needs to be delivered within two hours or there are problems.