I want to color my hair

Is there any natural way to color hair permanently. My hair is pretty dark, I henna once a month and I don't really see any color change. Other than those darn greys, boo! Is there a way to color hair naturally? I used to color when I was getting relaxers and had to stop because of the damage it was doing to my hair (thinning).

I would love some color but don't want to same thing to happen now. Haven't colored in ages.

Any ideas?

Thanks!

People say that honey can naturally lighten your hair, as well as (i think) lemon juice and sitting out in the sun (that last one sounds like it would be very drying though). If honey does work to lighten your hair, the henna color would be more pronounced.

Not sure of any other things that would naturally lighten your hair color off the top of my head.