Do filters exist that are primarily for showers, as opposed to drinking water?

I read recently that when hair color fades and dulls (I am talking about fake hair color, i.e. a dye job), it’s most likely due to minerals in the water. I am wondering if hair salons use a filter on their faucets for when they wash clients’ hair. I ask this because where I live, there are so many minerals in the tap water that the tea kettle gets something that looks like dried paint on the inside bottom. If that’s going on my hair every day (and skin), I am considering filtering it out, if such a filter exists.