Hey, Ive bred frogs for many years now,,
I have come across many white taddies in my time and usually there is nothing different in their development, i do agree with some of the above quotes saying that they would survive in the wild due to natural selection though as they are in the captive environment they have a far greater chance, If you are at all worried about their development or if there are begining to sprout legs and you think they may be a bit to fragile during metomorphosis my little handy hint is once you see the front legs coming out feed them up on blood worms or brine shrimp, its not the best for them when they are young taddies but when they're ready to hop out of the water it gives them a load of protein to help them put on a little extra weight.
With my white taddies once they became froglets there was a slight difference in colouration but as they go bigger the differences became less noticeable,,
hope this rambling helps