- gosh, I can't just go around answering eternal mysteries like that! The Harvester wears a hood for a reason - no one should ever see what is beneath it, or know the horrors of it. It's best to disguise itself in darkness to save everybody else.
Also, just as a comment to this colour suggestion - drawing anatomically correct skeletons in Subeta style (that is, very detailed) is extremely time consuming and difficult. There may be people out there that excel at it and can get it done quickly enough to fit in our budget, but we learned from steamwork that putting so much time into so much detail doesn't work out great for us in the long run. I can't speak for the entire future of Subeta, of course, but I know that at this time this isn't a colour we are able to consider :(