Just checked another thread and it says 2ml per kg repeat in after an hour if not better. Sending lots of vibes.
Yes plant polyphenols can make a Rabbit's urine very dark orange.
Is she drinking more than normal ?
I am wondering if she may have cystitis/a UTI. The pain from this could be enough to stop her from eating. It would also explain why the Vet said her guts felt OK. But having said that one would hope that an abdominal examination would include the bladder..................