Read the title lol

Probably. Like sometimes you see dyed emperors dragon nixis that are more expensive than regular.

just bc someone set higher prices dont really mean they are worth more.
it depends on the colors, if they dont look good you probably wont have anyone wanting to buy them.

No, actualy they are worth less in some case as they lose their values as themmed. Unless it happen to be a dye project with clear coloration (not muddy or dyed half way) they have the same value as a wild pet in general.

For the case of the dragon nixi, it's a bit different due to context, here is the short of the story :

There was no tag for pb back then so when people made dye project for this trait set they would not be advertised as pb dragon nixi but as project pets. Some people bought various project vertions from different breeders and then breed them togedthers to sell the traits set.
When the pb tag was added alot of the pets who were not seen as pb anymore due to coloration issue where added back by technicality, this added to the confusion on what was a themmed pet for new players as those false dragons were in fact pb but didnt had the right color pallet.
To fix the issue of those false themmed (not only for this themme but from all re-dyed pb/tagged) Krin made it so it would be possible to reset the original coloration of the themmed by using dye on them, it still cost you a dye (the average price of one lesser is about 80k) and it somwhat take care of the problem but there is still alot of muddy offspring for the dragon nixi themme avalable witch make that themme not a good exemple of dyed themmed.

I price my redyes (Cute Witch Zolnixies and Royal Elven Luporas) as more since they're projects. I wouldn't necessarily say they're worth more, but I just price them higher because, as I said, they're projects. The fun thing about having a dyed pair is that if you want normal-colored offspring, you can get both from your dyed parents (by hitting the color reset on the offspring).

Though, I'd only really consider redyeing Restricted trait themes, for the rest, the theme is simply a color scheme, so it's probably not worth it as much (unless you've got some pretty 6-vis or something and you want to change things up a bit. I'm considering this with some of my Hidden Heart rikkis)