It's hard to tell if its Red Leg. Being it looks better just since yesterday, I'm thinking no.

Keep him in a very clean tank, with paper towel substrate, as Chino mentioned. Rinse out his water bowl in very hot water. Allow to cool and replace with fresh dechlorinated water daily.

If he gets any more red, he might need antibiotics.

I would soak him daily for the next couple of days.

Is he eating yet?