Well, I think that is red leg. Are they lighter than the normal ADF? Are there any visible sores on the legs? Some frogs just have a natural pinkish hue to their skin. Their skin colors do change a bit especially when they're getting ready to shed. Here is a website with some pictures of what red leg looks like: http://clawedfrogs.tripod.com/id31.html
If a frog has red leg, it is usually lethargic and not willing to eat. If you feel that this may still be red leg, the best thing to do would be to quarantine the frogs, keep their water super clean, and treat them with Maracyn 2 (minocycline). DO NOT TREAT WITH ANY OTHER ANTIBIOTICS. Most antibiotics are toxic to frogs. Maracyn 2 is one of the few that are safe and readily available. Pimafix will not harm the frogs but it may be too mild if the frogs are indeed infected. However, my guess is that this is likely the natural pinkish color that the frogs sometimes have since they are still eating and active. I know that my 2 African Dwarf frogs have a pinkish hue to their legs and arms and they are definitely healthy and active. I hope this helps you.
Good luck!