http://i.imgur.com/I5oUf.png
My knowledge of the engine is pretty much non-existent, but I think this is pretty possible and shouldn't cause any real performance hit.
Thoughts?
I thought also maybe having each node (or whatever) in the 8x8x8 grid be customizable in color, but if none is chosen it would default to whatever voxed says the overall block's color is.
That way you could make something like these two blocks with only one custom block:
![Image](http://i.imgur.com/Beo1z.png)