How to make weapon's translations?

Hello everyone, i'm trying to use weapon translations. I already used it ALOT of times for monsters, but never for weapons. So i try using the basic format in my custom weapon: "Translation "112:127=181:191" (Example) so it doens't work. but THEN i go to the weapon sprite and changes mannualy, it appears normally (The image of the sprite translated in color remap) so i click OK and it doens't work either! Any help?