Wigs making mohair wig lighter

If it's a natural mohair fiber, you could maybe try using something like sun-in and leaving it in the sun to help lighten it. I'd hesitate to suggest using other kinds of developers and peroxides used to dye hair without knowing how it's made. Definitely do NOT use typical household bleach though! That will melt protein based fibers like mohair or other wools!
If the shade is close to what you'd like, and the wig is made in a way that you could dunk it in something, you can also try soaking it in chamomile tea and leaving it in the sun to help give it more golden tones as well, but that'd take more time.

 

It's like a very low level peroxide type spray that's meant to lighten your hair to a more beachy sort of look. I'm pretty sure they still make it, though the last time I had any personal experience with it was many years ago xD

 

There are amonia free hair dyes (Olia is the brand I use) that don't bleach the hair but dye it the colour of choice without the need to bleach (my naturally dark brown - peppered with grey these days - hair is currently a light blond, for example)

I've used human hair products on mohair wigs with some success, but those were usually for vibrant colours like hot pink rather than "natural" looking shades.

Teddy

 

I experimented with mixing hydogen peroxide and baking soda intoa paste, applying that to the mohair for a few minutes, then rinsing. I did that daily for about a week. This is damaging though. Even though I conditioned the hair, there was a visible and tactile difference in texture.

I've also used purple shampoo and conditioner meant to remove brassy shades on human hair. They worked well on me, so I figured to try it on mohair. According to color theory, purple is good for neutralizing yellow in these circumstances. It works, though it's more subtle than drastic.

 

Oooh! I hadn't thought of that one!!!

Teddy