One of the challenges we face from going from light blonde hair back to brown hair is making sure the hair stays rich and shiny and it doesn't look flat and dull. One of the things that happens when we make our hair blonde to begin with, is we take out what we call the undertones of the hair.
Naturally, hair underneath has many gold and red tones. As we made the hair blonde to begin with, we took out those gold and red tones. In order to bring it back to brown it's necessary to redeposit the gold and warm tones. From going from blonde back to brown, it's a two-step process at least.
First, mix up some golden-coppery tones close to the level or the darkness of the brown you're searching for. Apply all over your red and gold tones, just on the blonde hair. It's not necessary on your natural hair. Process for anywhere from 15 to 25 minutes. After, when you rinse it out, don't be shocked. I know it's not your target shade. But it's given us the base color for your target shade.
Now, what we're going to do is pick out a nice warm, rich brown. I highly recommend if your hair was blonde to stick with warmer, golden browns so the hair doesn't look flat and dull. After you've put your gold and copper tones in and you've rinsed them out, towel dry your hair.
After, apply your brown shade, which again I recommend a warm brown shade all over from roots to end. Follow manufacturer's instructions. I always say, though, when you're doing this kind of work, you should check in and wipe a piece off a few times during the 30 minutes to make sure it's going the way you'd like.
After all these processes are done, it still might be necessary to do a gloss or an all-over toner just to perfect the exact tone that you're looking for. This gloss or toner might enhance warm tones that are missing or it might diminish cool tones or ashy tones that are unwanted.
So, now you've heard the steps on how to go from light hair back to dark. As you see, it's quite a lot of things. I highly recommend you try it in the salon. But if not, here are some tips to do it at home.