Many old 1.8 utility mods (like Orange’s 1.8 Mods or Labymod ) include Fullbright as a feature.
Use a text editor like Notepad to open this file. minecraft fullbright 1.8
Find the line that says gamma:1.0 (or a similar number). Change it to a much higher value, such as gamma:100.0 or even gamma:1000.0 . Many old 1
Search for %appdata% in your Windows search bar and open the .minecraft folder. minecraft fullbright 1.8
Now caves, night, and the Nether will be as bright as daytime.
Resource packs are the preferred choice if you don’t want to mess with system files. These packs modify light levels directly. FullBright - Minecraft Resource Packs - CurseForge