It is my understanding that Ithaca lost the ability to redo case colors. They could not redo them so they tried a substitute with what many here consider a lesser treatment of torching or chemicals with heat to try to recreate case colors. The effect is less than desirable to most if not all.
Colt also had a problem many years ago. The secret formula/process was lost and they struggled to rediscover lost process. When you have only one or two people doing the work their retirement or death can create a major problem to makers. Many a great "secret way" has been lost because of this. Others try to rediscover what others have been doing for years.
