Fullbright 1.12.2 Texture Pack !link!

And the dark was winning.

Her last torch sputtered in her hand. She had ten durability left on her diamond pickaxe, a full inventory of ancient debris, and absolutely no idea how to find the surface. The cave system was a fractal nightmare of twisting dead-ends and silent lava pools. Every time she thought she saw gravel, it was just another shadow playing tricks. fullbright 1.12.2 texture pack

You can layer it on top of other texture packs (like Sphax or Faithful) to keep your favorite block designs while gaining the brightness effect. And the dark was winning