Yellow and Pink Fish Eggs--where do they come from? I've never seen them sold by the game or found them in explore or anything. 

These items come from past events, the only one which I was here for was the Easter one.

In those events, you'll be able to find items while exploring, usually fighting guardians, which can be exchanged for items at the Warlock Station, opened for that event, though I read that you were able to find the eggs from fighting guardians once as well, but I wasn't there for this.

I'd suspected it had something to do with the Warlock Exchange Station that I've often heard of and never seen. I was just somehow under the impression people were still getting them from somewhere...

I don't think it's possible to still get them now, but a lot of people get them from the warlock station in bulk and then have some left ages later. I myself have some pink ones left from the easter event :)

Okay, thank you!