Does hair coloring for many, many years ultimately cause hair to thin on top, or is this just a natural aging process?

Does hair coloring for many, many years ultimately cause hair to thin on top, or is this just a natural aging process?
I am suspecting that these and other chemicals, maybe even the chlorinated shower water, have been the cause of my hair loss. I don't like the red in henna, so I'm looking for some other kind of natural hair colour that covers gray. I think my scalp needs a break from hair colour.

My hair was thinning and finally discovered hair dye and perms were causing hair to break off at the scalp.

Take a hair and look under magnifying glass. If hair is straight across on both ends the hair is breaking off. If one end has a bulb like end, it means the hair follicles have released the hair.

It has been a year of letting color grow off my hair and no perms. Areas where I thinned now has short hair. I am so thankful at least some is growing back.