Having assembled a few Ghost Knight terminators for use with a Mordrak Grey Knights army that I'm building, I wanted to start to consider what colour schemes might be appropriate for painting the ghosts with. I noticed that a number of Ghost Knight images on the web tended to focus on greens and blues as the main hues. The major inspiration for these colours would appear to come directly from the army of the dead (Lord of the Rings). The image above shows such a colour scheme. Although the transparency is not really a viable option (I wish!), the general blue and/or green hue could be something cool to aim to emulate. I think I'm leaning more toward a pale blue colour than the green hues to be honest (the green makes me think more of a sickly cursed knight than a Mordrak ghost knight to be honest, but opinions welcome!).
The second point is whether to go for an all-ghostly colour scheme. By that, I mean should the Ghost Knights be a complete ghostly colour everywhere (whether that's green or blue biased), or perhaps should there be some of the original colours showing through in various regions? One alternative option might be to have only some set portions of the armour in the ghostly colours -- specifically the lettered portions on the shoulder pads (and elsewhere) to give an ethereal "inner glow" approach.
The weapons are another area that I don't know how to approach. Should they be "powered" like some other power weapons (e.g. see these terminator's power weapons), or should they be in the same colours as the "ghost" portions of the miniature? Your thoughts welcome!
[image from Lord of the Rings motion pictures; posted here in accordance with "fair use" guidelines as a reference material]