When you guys dye a pair and the stitching turns dark grey how do you guys get it back to white?

This is my attempt at making the stitching white again with paint. The pockets have 3 layers of paint and everywhere else currently only has 1 layer. The end result is good but It’s very tedious.

This is my attempt at making the stitching white again with paint. The pockets have 3 layers of paint and everywhere else currently only has 1 layer. The end result is good but It’s very tedious.