I was wondering. Does reform stone workin? I see i can use them with black spirit but does it actually work? Changing from green to blue?

No blue in game. It's removed. Only gold

Not worth it to pump regular reforma into weapons and gear. Farm hunter seals and exchange them at tarif for grad 3 reform stones.  Take 10 of these stones and heat them with a sharp or hard crystal shard and you'll end up with an ultimate reform stone. Guaranteed ultimate.