I'm new to LV, but have seen and known about them for years. The monogram bags are trimmed in vachetta leather that naturally darkens/patina over time. I thought that was one of the good things about the bag, but now I wonder. I see where a lot of people are having the vachetta replaced if it gets to dark or are trying to keep the vachetta light. Is this just preference or if the leather gets to dark, does it mean it is wearing out? Thanks!