Adding highlights to a wig?

So, the deal is, my BJD obsession and my Harry Potter obsession have like collided, and I'm hoping sometime soon to get a boy to customise as Prof. Lupin (currently have my eye on an SD13 FCS F-20 boy; owch, sticker shock! :cry: ).

But anyway, he's described as having brown hair with some grey in it, and that's kind of a tough thing to find. I've got my eye on something at Reve en Popee to have it custom-made (when I get around to working it into my budget), but I also happened to recall that, left over from my 1/6 Dollfie days, I have some lovely silver rooting hair around, so using it, I thought, I should be able to add gray into a wig myself.

So I wanted to write in and ask if anyone had done something like that and/or had any advice on how to tie/attach the added hair to the wig. Thoughts?

 

Thank you! Hopefully I'll be able to order him within a few months...

Anyway, I was browsing Torame's site and ah, couldn't read the Japanese, but one page showed just tying knots in the ends of little locks of hair and threading the other end onto a needle, and just putting them through the wig cap from inside, so that they wouldn't pull out from outside, but you could pull them right out from inside if you wanted. (I might experiment with melting the knots so they wouldn't work themselves out.)

I think I'll try that---and just get his wig in plain brown so I can (maybe save a little money, but mainly) have fine control over where the silver is in it.