Go to Options > Resource Packs > Open Resource Pack Folder .
You no longer need to carry stacks of torches or brew Night Vision potions, freeing up slots for weapons, blocks, and golden apples. How Fullbright Packs Work: Internal vs. External fullbright resource pack 1.8.9
Launch Minecraft version 1.8.9 (ideally with OptiFine or your preferred PvP client). Go to Options > Resource Packs > Open Resource Pack Folder
Note: If you are using a custom texturing pack alongside Fullbright, make sure the Fullbright pack is at the of your selected list so its lighting rules override the other packs. Troubleshooting: Why is my Fullbright Pack Not Working? freeing up slots for weapons