Hello, my friend has a melasmic axolotl and his feet have begun to turn white! They used to be dark just like the rest of his body. He is acting a bit lethargic as well. He is fed earthworms, and his tank is between 66-68f. His tank has been established for quite a while (he is 3 years old and has had maximum of 50% water changes done) here is a photo of his feet.