i am actually giving our specimen the 'cold shoulder' this winter, as am not big on sheltering plants. If it survives our 15-20F winters outdoors and naked, i will definitely update this thread. And likewise if it succumbs. Our finger lime actually bears maroon/brown fruits, not the green ones or the pink ones, and like you , am interested in the other colors, in the hopes that anyone of them might be hardier to cold weather than the cultivar we have.
i agree, it has its own unique flavor and texture but it is probably the rarity which make it so expensive. I linked the following as this thread's sequel, if you haven't seen it yet.