I don\'t think you\'ll be boring to look at. Of course you will have the normal selection of different parts and features at character creation.
You could also have a whole host of customising options with the veining. At character generation, as well as selecting from the basic greys/blacks of body colour, you could also customise the colors, density and patterns of the mineral veins to very individual styles
If you want further customisation in-game, then maybe a Kran specialist shop or character. I like your idea, he could add designs in much the same way as a tattoo, but like you say, perhaps chiseled in (ouch!). Or make other modifications with a molten silicon compond.
Will you still get to wear stuff like capes and other non restrictive clothing? Plenty of customisation there