Is there a way to change I can change my pets species w/o changing her color?

Yes.

Miracle Potion II

In most circumstances, it'd be easier just to change your pet via an elixir, and then repotioning it to the color you like.

any way that wont cost a fortune?

Well, what pet do you wish to change the species of?

No, the only official ways are via elixirs, or via Miracle Potion II.

Kimberleigh

The cheapest thing for you would be to get a pet elixir to change Kimerleigh's species, and then to repotion her glacier.

There's no other way besides that. xD

thanks then