I noticed that some class items don't change color based on your shader but will alter its specular maps to that of the shader. I've only noted this on cloth based class items such as those for Hunters and Titans. This isn't for all class items as some will still reject shaders entirely. Primarily ones added by the April update, but I only have so many class items to test this on so it may extend to others. On the ones it does affect though it makes for a interesting variation on some class items we're used to not changing. TL;DR : Equip Strength of the Pack and Glowhoo.