grass_block_graphics_fast.json information
// by Sencie https://www.planetminecraft.com/texture-pack/old-lighting-amp-old-water/

This is the default side of grass blocks (pre-Beta 1.5). It is not affected by the biome temperature.
It was possible to have it with the setting "Graphics: Fast" until version 1.7.10.

To use it, delete grass_block.json and rename grass_block_graphics_fast.json as grass_block.json