2017 d penny decoloration 0

[Vero86]

I have seen some posts over this, but not sure what causes it, can someone help, this are 2 pennies from 2017 d, one is colored as rainbow with some white marks, , the other has part of it with another color. Sorry do not know how is this call.

[Mohawk]

That would be some environmental damage, which is caused by the metal the coin is made of chemically interacting with different chemical agents in the environment.  This is extremely common on Zincolns as copper and zinc are both highly reactive metals and zinc becomes even more reactive when plated with another metal.

[GBrad]

Your second pic of the obverse also looks to have some roller damage on it too.