This is a particularly fascinating case: only the dark band is from hair color regrowth!
This client had an experience of dramatic inability to process nutrients properly. This light band is actually the result of the resulting malnutrition, and the deeper line at the scalp is the result of getting that back under control.
I did filter this photo slightly to increase the color difference to make it more visible on a phone or computer screen, but that difference showed up noticeably in person. I’m posting this photo along with this information because I feel it is important for stylists to know that this is something that can happen. It has no effect on how the color processes typically if going darker, but sometimes the client may not notice a difference like this and it’s important to bring it to their attention because it may relate to underlying undiagnosed health issues.
In this case the client knew she had been having issues and she went through medical care to correct before I saw her, which is why there is a light band and then her natural color started to grow back in again. I’m happy she’s safe and healthy again, she’s always a delight to be around.