No, when i get him 5 month ago, he was smaller and did not have those white spotDid you just get him? Some of them look like normal coloration for a wild type axolotl (mine has a few light tan spots), but some of them, especially on and near the limbs, look a little bit suspicious.
Hopefully, it isn't something "bad". Some axolotls lose pigment (vitiligo), and I don't believe that is harmful in itself.
Does the skin where the spots are look different (other than color) from the surrounding skin?
If it is vitiligo, it isn't dangerous. I don't know if it always progresses or if it might just stay the way it is.
If doesn't look like the pictures I've seen of vitiligo, but it doesn't look like the pictures I've seen of illnesses either.
Keep taking pictures every week and see how it changes. Maybe how it changes (or doesn't change) will give people a clue.
If he seems healthy otherwise, just continue to take good care of him and try not to worry. If he has any other symptoms, then post them too.
He looks perfectly healthy and I would attribute your spots to normal iridophores.