Shader customization. For say 1 strange coin or a few motes you get to choose a color from a color wheel of sorts for one piece of armor per character per week. There will also be faction decals available, but you need to be rep 3 or higher within that faction to buy them using glimmer. They come in a limited selection of colors. Once reaching rep 3 with my customization vendor, weapon re-skinning is unlocked. Although simple color re-skinning it allows more customization. Exotic Weapons and armor are not customizable. Sorry.