Help with piston rings

[Tether]

So I’m getting ready to install new rings on one of my Wombats. The new rings came, one is black and one is silver. I don’t see any other difference in the rings. My question is: which one goes on top? Does it matter?
Thanks,
Bob

[thrownchain]

Silver on top.

[Tether]

Thank you!
Now for the dumb question, why?

Edit:
The silver ring is chrome, harder because it is subject to more pressure. According to what I found on the inter-web. I just like to know why.