Is there a list of what pet colours cannot be zapped?

Angelic cannot be zapped, I don't think Galactic and Hydrus can either.

There might be other colors.

Riftborn can indeed be zapped. Got a riftborn warador the other day.

Nostalgic and steamwork are two more colors that cannot be zapped. I'm not totally sure, but I think sweetheart is also unzappable.

That should be fixed, imo - if Blacklight can be zapped, Sweetheart should be

The FAQ says: Angelic, hydrus, galactic, nostalgic, steamwork, and sweetheart are not available from the zapper.

Blacklight, isn't that the opposite of spectrum? Spectrum is zappable, according to this.

Yeah, Spectrum is zappable - like all of the Token Shop potions. Blacklight, which is a CSC color also is.

My point is more; if the potion that's 250 CSC can be zapped, why not the one that's 100 candy hearts? ;)

Thank you everyone for your help xx