The app selects the "right color" shard/rune, but you can use a different color and it also works. Does it take more shards for the same leveling, does it cost more gold?

Colorless shards/runes. Do they work on any color resource, but with equal effectiveness? Equal cost?

Or are they meant for "Cosmic" leveling ??? Should I be saving them? Using them?


Asking because this info isn't available anywhere.