Red Lightning was a rare Force Power created by Darth Rayze during New Jedi Order Era. It was thought to be a powerful variation of Force Lightning and was sometimes known to leave the victim devoid of the Force.
Darth Rayze is the only confirmed user of Red Lightning. Darth Validorn also attempted to use this power on Darth Rayze, though it is unknown how he learned to do so.
It has been speculated that Red Lightning is just Force Lightning whose Lightnings temperature is so highly intense that it is red from heat. This is, however, purely speculation because victims of both Force Lightning and Red Lightning in their duality have said that they feel different and have different effects.
Many variant Force powers have been created from the fundamental of creating Red Lighting, as said by Jerun Othorne. Instead of being a projection of elemental lightning energy like Sith Lightning, Red Lightning was a gathering and releasing of cosmic heat and could also be used to drain a Force-User, hence Red Lightning’s Force Strip like abilities. After the Dathomiri Witches observed Darth Rayze casting Red Lightning and observing how he manipulated Cosmic Energy, they created Force Barrage, a much more powerful Force power but that which is based from Red Lightning’s fundamental.