Any harm in upgrading RAM with another of the original kit?

So I built a great PC 4 years ago that I'm about to do some upgrades on. Link here if you're interested: https://forum.teksyndicate.com/t/best-choices-for-upgrades-to-a-4-year-old-rig/85093/4

So the RAM I got was this. http://www.newegg.com/Product/Product.aspx?item=N82E16820145324
I figure, rather then shelling out a boatload of money and getting a 16 GB kit, why not just buy another of these 8 GB kits and throw it in my rig. Is there any harm in doing this?

You can mix and match RAM, it'll just run at the lowest speed of the group, which won't matter all that much.

So aside from aesthetics you could throw anything in.

OEM like HP mix and match ram.

Buying two separate kits of the same ram is fine. Just to be mental make sure you have the kits in separate channels (colored coded sockets).

I did not know that about RAM. For some reason I thought that it was important to have all the same in a rig. Huh. Thanks!

That's easy to do. Thank you for the suggestion.