One more thing to try - white pencil eraser like the Staedtler Mars plastic brand.
Also, if you notice it getting worse around the piping, it could be defective glue. This is what was happening before to the white multicolor pieces where the glue that was used started to yellow after a few years. It's a known problem and LV should exchange it for you if that is indeed the problem. Never seen it with an azur piece though... plus you did mention wearing a brown SUEDE jacket with it?!
Also, if you notice it getting worse around the piping, it could be defective glue. This is what was happening before to the white multicolor pieces where the glue that was used started to yellow after a few years. It's a known problem and LV should exchange it for you if that is indeed the problem. Never seen it with an azur piece though... plus you did mention wearing a brown SUEDE jacket with it?!