Caves, ravines, and night scenes appear as bright as noon.
Unlike a typical "resource pack" that changes how grass or stone looks, a Fullbright pack leaves the aesthetics untouched but forces the game to render every block at maximum brightness. It’s like having a permanent Night Vision potion that never expires and doesn't produce those annoying swirl particles. Why Use Fullbright on 1.8.8?
If your game is still dark, ensure that the Fullbright pack is placed at the top of your active resource packs list. If you are using OptiFine or a client like Lunar or Badlion, check the client settings to ensure that "Custom Sky" or internal shader options aren't overriding the texture pack. Does Fullbright cause lag?