Comment 9 for bug 1393485

@nik90 right, this should also apply to header icons. Actually, with the latest palette update that was taken care of, but I need to make sure that the opacity is not multiplied with 0.3 twice (once from the icon, once from the palette) for disabled header icons.

That also makes me think that perhaps the icon itself should never change its opacity, but the component that uses the icon should set it for all its contents.