While I'm revealing my tricks, isopropyl alcohol will dissolve dried acrylic paint.
If you look very closely, you will see the effect on the piles, where I've blended the black stain upwards into the grey.
So, if you paint ties black/brown - what ever looks "right," you can improve the look by blending with IPA.
You need to rub it a bit. (Elbow grease).
Cheers