To say that indigo is "having a moment" is something of an understatement. Not only is it one of the oldest dye stuffs in the world, but a slew of brands both big and small have been opting for the natural dye lately. The result? A wide range of inky, midnight blue products that look good on just about everybody. Of course, there are tons of clothes on the market that use the word indigo in reference to a garment's color that have nothing to do with the actual pigment or the unique oxidation process that causes such a distinct coloring. These here were all made using pure indigo, meaning that they'll likely fade (and get better looking) with each wear.
What a Crock: Indigo dyed fabric is prone to a color transfer called "crocking" where it rubs off on things. This is because the pigment never actually chemically bonds to the fabric. It's simply lodged into the fibers at a microscopic level, so eventually it breaks free and wears off.