Have you ever thought about how blue blackstone is? I mean, it truly is a blue shade, which can ruin the feel of the nether at times. Plus, it means the only truly black building block is black concrete, which lacks texture. Well, Vantablack revamps all 6 blackstone textures, and changes black terracotta to be more black based than red based.

Blackstone will have a darker shade.
Polished blackstone will have a darker shade and be smoother.
Blackstone bricks will have a darker shade and stacked vertically, which really adds to the looming height of bastions.
Cracked Blackstone bricks will look just as blackstone bricks will, but will have small red cracks in them.
Chiseled Blackstone will have a darker shade.
Gilded Blackstone will look similar to nether gold ore, which makes it much more of a usable building block than it previously was.

V1.1: Blackstone will now utilize Optifine's alternate blocks option to make blackstone look more natural