How to reset the material of my object on instantiation during run time

Hello All.
I am new in unity coding in c#.
I am building an endlesss runner where my environment instantiates at regular intervals.
In my environment I have a few objects with a specific material.When my player collides with these objects their colour changes so that i know they are collided with.Now I want to reset the material of the objects when the environment instantiates. How do I go about doing this??
Thanks in advance.:slight_smile:

Second example in this documentation is relevant.