I suppose I was ideating the concept of "organic" plates of armor... though that more readily applies to Vasudan designs. Most Shivan designs seem to have a "carapace," even the Demon-class destroyer has this aspect. In short, I was entertaining the idea of "scaly plates of armor," making for an organic appearance. To make it look armored, I was suggesting the dark texture in reference to the Rakshasa... this is due to the texture of the Rakshasa itself, which lends itself to greebling... and greebling has a good way of making something look armored.
Basically, that was the thought process at the time. However, given how tough the "grey Shivans" are (the Demon, Ravana), a grey Lilith is also very plausible.
-Thaeris