Cause of the boots.
Use white wand paint or dull white spray paint anything like this.
Paint them up with it.
Than use very diluted dull black paint , paint them over.Just a very thin layer ( so that you can see still see the white paint)
After it use again a very thin layer of the white paint.
Do less white paint on marks like the kick pleat or the toe cap.
Than add some scuff marks with a piece of rubber or a newspaper.
Mine looked after it like this:
Comparsion: