Can anyone explain it to me? I don't understand a word of it.
All I can say is already covered in the Tutorial.txt doc file that comes along with the plugin. It basically allows you to add a flashlight spot as well as tint the whole scenery provided your game is designed for the hi-color mode.
Try some of many examples of scripts from "Tutorial.txt".
A common one is as follows:
Player enters screen (before fadein):
// script for room: Player enters screen (before fadein)
Ã, // set darkness so dark than you can still see a little bit of the background (+3)
Ã, SetFlashlightDarkness (GetFlashlightMinLightLevel() + 3);
Ã, // set brightness to the brightest value
Ã, SetFlashlightBrightness (GetFlashlightMaxLightLevel());
Ã, // define the outer circle (outside it will be dark)
Ã, SetFlashlightDarknessSize (50);
Ã, // define the inner circle (inside it will be bright)
Ã, SetFlashlightBrightnessSize (20);
Ã, // set this to have the light spot follow mouse movement
Ã, SetFlashlightFollowMouse (1);