Orange because cinderellas shoe didn't actually fit
What mariusthered said, plus I think you'd get sick off your own blood after just so many liters anyway.
Dehydration perhaps, blood makes you vomit.
not long. You can't feed on your own blood.
You can survive for a short amount of time drinking someone *else's* blood (it's dehydration you're staving off, starvation takes much longer), but you can't stay hydrated drinking your own bodily fluids -- and even if you could, you'd die from blood loss...