How to make stitching resist dye after assembling?

[Lollappaloosa]

I have kind of a unique question, hopefully somebody here has a suggestion. I don't make my own leather tack, I just buy it and customize it to match the rest of my stuff. My saddle is dark chestnut with aged white stitching, I can find tack with white stitching but usually the leather needs to be dyed to match the saddle color. I really like the way the light stitching contrasts with the darker leather. What can I use on the stitching to make it resist the dye so the finished product will match my saddle? Any ideas are appreciated. Here is my saddle so you can see what I'm talking about.

Here is the type of tack I want to match my saddle:

[hidepounder]

You may be able to darken the headstall to get it closer to the color of the saddle by applying a light coat of Neatsfoot oil and then putting it out in the sun. You might try it in the sun without adding more NF oil first....it looks like the headstall has been well oiled. I don't think there is any way to preserve the white color of the thead while dying the headstall. I could be wrong, however, and will be watching the responses to see what others might know, LOL.

Bobby

[Lollappaloosa]

I tried neatsfoot oil but it still wasn't near dark enough. I tried clear nail polish as a resist but some dye still soaked into the stitching. I wonder if block out would do the trick? Or if I would better off pulling the stitching and redoing it with white thread after I dye it? That would be a lot of work but might be the best solution. I'll see if anyone else has any ideas....

[MADMAX22]

I have no suggestions for ya as far as keeping the thread from dying also however if you have the tools you could always use that headstall as a pattern and make your own just dye it the correct color to match the saddle. Probably wouldnt be any harder in the long run then taking that one apart and putting it back together again. I know its not cost effective though.