If you frequent this store and are otherwise satisfied with it, I would educate the shop owner about the process, about how un-natural it is and that some will only buy this frog because of the color, what will happen to the frog, or his reputation, when the color fades? And are the few extra sales worth that?

I have found that if I have a good relationship with a store owner and calmly, very calmly (and sometimes with a little humor), explain my concerns for the creature and for the store (more importantly), the owner generally will do what I want, which could be as simple as posting a notice such as "that these frogs are un-naturally colored" , also explaining just how delight ACF can be, in this case.

I recommend that instead of just walking away from a store you have had a good history with, try to educate so that every creature purchased would be wanted by the buyer for what it really is and for its natural life span. Its better for the creature and actually better for the store.

I have certain favorite stores, and the owers are so used to me being a brat (or is it a different "b word"?) that I get away with too much, including changing descriptions and getting major discounts.

As our mothers used to tell us "you catch more flies with honey than you can with vinager".