I have these shoes that I've worn for a few years, but they're actually still quite okay, if it wasn't for the washed-out color. That makes them look very worn out and battered. The fabric is linen and they used to be a denim-style dark blue. I'd really like to give them back some color so I can keep wearing them, but short of painting them all over with a thick marker, I have no idea how this could be achieved with lasting effect. I mean your standard methods for dying fabric (which I don't know what they are) are probably predicated on the fabric not being sown to a rubber sole etc. - right? Any suggestions would be much appreciated!