Top texture of grass blocks appears pitch black in the Dark Forest biome when Smooth Lighting is disabled

All grass in Dark Forest biomes, no matter the light level, whether it's been replaced or placed in Creative, is pitch black. I would expect it to be a dark green, and it is not.

Steps to Reproduce:

1. Locate a Dark Forest biome

2. Go to Settings > Video

3. Disable Smooth Lighting under Simple/Fancy Graphics Options