Can be toggled on and off at a press of a button, default bind is L
2 colours: blue and red
Client side only
1st person only
How to change the colour:
In the mod folder, navigate to mod\scripts\vscripts. You'll find a file called s2_weapon_laser.nut there, open it with a text editor (normal notepad will do)
On the first couple of lines you'll see a struct called settings, change the highlighted value inside as instructed (see screenshot)
Save the file and start your game/click reload mods in the mod section, your changes should be applied