Returning to Natural Hair Color After Dyeing?

So about four weeks ago, my aunt bleached my hair and we dyed it gray a day later (to the ends). It faded out in like 2 weeks even though it was supposed to be permanent hair dye. Now after 2 more weeks of having a weird bleach line going through my hair, I've decided I want to go to my color before I started this whole process. I still have highlights from before I started the gray process.

So, can I dye the ends of my hair back to my original dark brown, then have highlights put in? I want to keep highlights because I want my hair to be as natural looking as possible, but my original dark brown color sounds really intimidating. Help!