Her stupid prison hair

I get that she can't continue to bleach her hair while in prison, but she can't continue to color it at all, then, right? And she's been in there for a few years now, yes? So why do we see her roots? Her hair is significantly darker than the original bleached blond, but then her roots are even darker than that, and have a clear line showing where the natural root color meets the lighter color... and it's maybe a couple months of growth. So what the hell?