Hair dye verses shampoo colorants/

I have been coloring my hair with a permanent hair color that contains no peroxide or ammonia (Robert Craig) for about 1 year now. I have noticed alot of breakage lately and I am not sure what is causing it since this product is supposed to be getle to your hair. I shampoo and condition my hair well so I want advice on maybe trying another haircolor that is very gentle or possibly trying the Aveda, Artec or Paul Mitchell haircolor shampoos and conditioners. My natural haircolor is light brown and I dye it a medium auburn. Can anybody make a suggestion what to try as I am willing to see if this would help my hair from the continued breakage. I don`t have any grey so that is not a concern. Thanks