So for mine I used leather dye black to do it and then when I went over my jacket again with a dabbing sponge to dye the suede again it kinda automatically dimmed the stitching down.
However, I’ve been trying for months to dim down the stitching on the jacket, I’ve tried sharpies, water dye, leather dye, and suede dye. So I did a lot of trial and error. But soon enough, I’m going to be trying Jacquard idye to see if it makes it darker. Right now the stitching is a light or dark gray, you can barely see it in regular lighting, but it still bothers me.
The reason the thread on the jacket didn’t dye is because it’s a synthetic material and you’re probably gonna have to die over it a couple times to get it to the opacity you like, so that’s why I’m gonna try out Jacquard idye.
I’ve tinkered a lot with my jacket since the last time I posted an update. I dab dyed the suede again to get rid of any imperfections in the coloring so I can look like one solid color in the light, I’ve dirtied the collar with grounded, coffee, and a little bit of paint, and I’d even died the side panels of the jacket, a darker color.
If you want, I can post another picture of my jacket.