if your looking for a natural colour i would say try henna. i just henna'd my hair last weekend, and its great! its really improved my hair so much it looks like ive had a new hair make over! haha im naturally a bright red head, so i went a light reddy brown, so now its gone darker and has a brown tone.

my hair: 3b, high porosity, high density and coarse hair (i think i finally figured that all out)
my hair loves conditioner only styling!
Oils and my own procuts are my hairs best friend
my hair goal length is bra strap length when curly.