I do.
I darken it.
It's a strange situation. I was a blond kid. However I hated everything about myself and in a symbolic gesture of flipping the bird to childhood, as soon as I graduated sixth form we had to move away to another part of the country, and I cut my hair and dyed it black. I was sick of everything at the time and wanted to see the opposite of what I saw in the mirror. I think even my clueless parents understood how I didn't have a great time as a child and wanted to leave it behind.
Anyway, it turned out I was fond of black. All through my university years it was black or sometimes red, but not once did I grow it out. I got pretty good at dyeing my own hair. Nobody in my adult life had seen my natural hair color, including me. I hadn't seen it for 18 years.
Last year I got curious and decided to grow it out. It wasn't blond any more but brown. It weirded everyone out. It even weirded me out at little as the last time I had seen it, it was far from brown, and I couldn't even describe the sort of brown it was. The closest I could come to describing it would be "rat brown", lol. For some reason my eyebrows are darker naturally and fit having black hair just as much as they fit the darker brown.
People wouldn't let it lie and kept saying how weird it was, how they didn't like it, and tbh neither did I. So I got a bunch more dye for the year and went back to black. Permanent dye is probably bad for hair but I've never had any ill effect and it always makes the hair feel and look better. So what the hell, I see no reason to stop.
Hypothyroid issues a couple of years ago cleared up but they permanently affected a small stripe of hair on my left temple which is now pure white. People think I'm dyeing only to hide it. Lots of Just for Men jokes