There are 4 versions of this pack:

DEFAULT: natural lights and shading, including reddish artificial lights and dimmer nights.

BRIGHT: as default, but roughly as bright as vanilla.

SHADING ONLY: as default but only affects sun/moon light and shading, artificial lights stay white as in vanilla.

FULL: changes everything including how Night Vision potion works (blueish lighting, less visibility under the sun) and special effects to the Nether (everything is reddish) and the End dimensions (very dark, even lights are dimmer). This is the version you get in regular Pixel Reality.

---

HOW TO:

1) go to /assets/minecraft/mcpatcher/
2) open the chosen version's folder
3) copy the content of the folder
4) go to /assets/minecraft/mcpatcher/lightmap
5) delete the content of the folder then paste the files you copied before
6) save and close.

"Default" is included as backup in case you want to revert changes made.