I remember when my hair was Just like in the awkward stage but it didn't stick up. And now its a little down my back and before it was pitch black a little Browning at my hair line that has now got my whole frontside of my hair brown and black. It looks highlighted and very dark on the back. My hair is thick and thin on my front and on my back its really thick. Haven't seen split ends only on the lighter parts. I was thinking of dying my hair with Coffee but I think it should stay since it doesn't look bad. I don't want to use the chemical hair dye because my hair hasn't been straightened, dyed, and hasn't really had anything done to it. I Dont use any shampoos besides Hugo's naturals and matrix essentials when I use olive oil. It uses chemicals but its larger isn't very bubbly and doesn't strip my hair much. But I usually use the all natural one
How about a photo
Is your hair exposed to sunlight? What you describe sounds a lot like sun bleaching. It's natural and won't harm your hair. If you want the even dark color, consider a temporary color rinse. Chemical dye kits damage because they frequently use peroxides, especially if you go shades lighter than your natural one. Color rinses to add lowlights or darken hair are typically peroxide-free, and are temporary ones that gradually fade with each shampoo. There are ones that use natural dyes from herbal preparations. Many have the added benefit of nourishing and conditioning the hair strands.
You may just learn to like the brown highlights. You may also be developing multi-tonal hair, in which you have several natural shades. I have everything from dirty to sandy to honey blonde, with strawberry blonde mixed in. It's not uncommon to have hair strands vary in color, even on the same strand. At age 50, I now have some white mixing in with the above, mostly along the temples. I do temporary coloring to highlight and enhance my natural color.