Axolotl color change

[TheReefer]

My axolotl (20 inches or 25.4. Cm) is in a 20 gallon tank and has had some weird spots show up. They aren't bumps, fuzzy or anything like that, water parameters are fine and my axolotl is acting fine, still eating normally, and the water is still good. I presume this is just a natural change and nothing to be worried about, but I wanted your guys opinion on it.

 

[THOSranger]

Kind of late but are you including the temperature of the water when you say parameters? Axolotls require cool temps and will get spots on their skin when under stress or in hotter temps.