Why do the Sith only use red lightsabers?

Ever since George Lucas’ Star Wars first appeared on the big screen in 1977, audiences of all ages have been drawn to the epic sci-fi conflict between the Jedi and the Sith. Aside from the incredible X-Wing dogfights with TIE fighters, vast universe of memorable characters, and the complex building of interstellar communities across the galaxy, the battle between the Sith and the Jedi has always been the major draw for fans of the massive space saga. In fact, without the Jedi, Sith, and lightsabers, Star Wars might not have become as popular as it has.

40 years and several generations later, the lightsabers themselves have become the most recognizable aspects of the Star Wars universe. Over the last 20 years in particular, we’ve seen dozens of various lightsaber designs, colors, and origin stories. From the original Star Wars trilogy featuring Luke Skywalker to the new Force Awakens trilogy with Kylo Ren, lightsabers have evolved dramatically. 

As long as they’ve existed, the Jedi and the Sith have always been on two opposite sides of the Force: the light side and the dark side. Those designations have typically been reflected in the colors of their lightsabers, with the Jedi usually wielding a green or blue lightsaber and the Sith are often recognized by their menacing reds. For years, fans have wondered why the Jedi have different colored lightsabers amongst them while the Sith always seem to have red ones. Why are they red to begin with?

How to understand the Star Wars universe 

According to Movie Web, with the exception of the two movie trilogies, everything Star Wars that existed before The Force Awakens has been wiped from the official canon. This includes all past novels, comic book stories, video games, toys, and anything else that was previously tied into the franchise pre-2015.

All of that information has now been neatly packaged and placed on a shelf under a new name: Star Wars Legends. Since that time, Disney and Lucasfilm have worked tirelessly to make sure all new tie-in properties are directly connected to the movie universe as we now know it. With Disney’s purchase of the Star Wars franchise and the Legends canon pretty much thrown out the window, the door has opened for new lore to be established regarding lightsaber construction and blade color. Before we get into the new canon of lightsaber history and fun facts, let’s take a look back at what Star Wars scribes first believed about lightsaber history.

The power of lightsabers

To understand what determines a lightsaber’s color, we first need to understand the source of their power. Luckily, that’s one thing that hasn’t changed in the last 40 years. Kyber crystals are the main power source for lightsabers in both the canon and Legends. In the canon, younglings mine for kyber crystals in the Crystal Cave of Ilum, which is an important part of the Jedi tradition. These crystals are usually colorless until they bond with a Jedi over the Force, with most ending up blue or green.

In Legends, kyber crystals are also found in the Crystal Cave of Illum, but these caves exist on Dantooine and the Adega system as well. These kyber crystals already have colors attached to them, but both Jedi and Sith had to imbue them with the Force before placing them in a lightsaber. This is where the canon and Legends veer from each other. In Legends, most Jedi use natural kyber crystals whereas the Sith use synthetic red ones that are filled with the negative energies of their creators. These red crystals were said to boost a dark side wielder’s Force and offensive abilities. In Legends, not all lightsabers are made of crystals, either, as physical remains, shards of glass, and even special micro machinery have also been used.

The new canon of lightsaber history 

All of that changed in 2016 with author E.K. Johnson’s Ahsoka, which follows Anakin Skywalker’s former Jedi apprentice first introduced in the Disney animated series Star Wars: The Clone Wars. In the book, Johnson had a very different answer as to why Force users who are swayed to the dark side always have red lightsabers instead of the predominantly blue or green blades of the Jedi. Since then, it has been widely accepted as canon by Disney/Lucasfilm and the fans themselves, leaving the history of Legends behind as pure myth.

In Ahsoka, it is revealed that all naturally-occurring kyber crystals are actually Force-sensitive and colorless. They choose their desired users and present themselves to the Jedi in question, and during the “attuning” process the crystal gains its final color, as reflected in the Jedi’s blade. Those who use the dark side of the Force, such as the Sith, don’t have this unique connection to the crystals. Because natural kyber crystals are attuned to the light side of the Force, they are naturally resistant to a user of the dark side. In other words, a Sith can’t just grab a natural kyber crystal from the wild and use it, as they would not be able to “attune” the crystal to them.

The only way a Sith can get ahold of a kyber crystal is by stealing it or taking it away from the defeated Jedi. According to E.K. Johnson, the crystal loses its original hue as the Sith or other dark side users of the Force bend the kyber to their own will. To do that, a Sith wielder must fuse rage, hate, fear, and pain into a kyber crystal by means of the dark side of the Force. The trauma of being forced to bend to the Sith’s will then results in the kyber crystal “bleeding,” thus giving it and the lightsaber a crimson red hue.

What happens to a defeated Sith’s kyber crystal?

As E.K. Johnson dove into the source of a lightsaber’s color, she also found a way to use Ahsoka to tie in another colored lightsaber ⏤ the white lightsaber ⏤ which has only been seen during Ahsoka’s time on Star Wars: Rebels and the second season of The Mandalorian. Many fans of the series wondered about the significance of the white sabers and their connection to the Force. As it turns out, they’re just as connected to the Sith as they are to the Jedi.

According to the novel, it’s possible for a light side Force user to heal or purify a kyber crystal that was previously corrupted by a Sith. However, even though the crystals may be purified, they will never again return to the original color of their previous Jedi owner. Instead, they turn a white color. As it stands, Ahsoka Tano is the only known example of a Force user who was able to do this, and fans of the animated series will remember the time she purified the crystals from the blades of the Sixth Brother, an Inquisitor she had killed after the end of the Clone Wars.

So why do other Jedi have different-colored lightsabers?

Although there is now a more modern and  plausible explanation as to why a Sith’s lightsaber is usually red, there has yet to be an exact explanation as to why Jedi lightsabers are able to come in various colors like blue and green, especially since kyber crystals are supposed to be “colorless.” However, in the Legends expanded universe, there are different colored kyber crystals and designations to help determine why certain Jedi wield a particular colored light saber and why we sometimes find those same Jedi wielding different colors later on. Apparently, the colors are meant to symbolize a Jedi’s progress and rank as a guardian.

The blue lightsaber

Blue lightsabers are among the most commonly-wielded weapons in the series, with Obi-Wan Kenobi and the Skywalkers commonly seen with it. In Legends, blue crystals are typically given to Jedi guardians, who use the Force on a physical level.

The green lightsaber

Green lightsabers are also common and have been wielded by the likes of Qui-Gon Jinn, Yoda, and Luke Skywalker. These lightsabers are traditionally given to Jedi Consulars in Legends, who serve as scholars of the Force and seek to fight the dark side at its core.

The yellow lightsaber

Yellow lightsabers were wielded by the Jedi Temple guards in both canon and Legends. Some canon yellow lightsaber wielders include the Sith Asajj Ventress and Rey in The Rise of Skywalker. Yellow crystals were typically given to Jedi Sentinels in Legends, who honed their skills in both combat and intellectual pursuits.

Other colored lightsabers include Mace Windu’s purple lightsaber and the black-bladed Darksaber seen in season two of The Mandalorian. Currently, there hasn’t been an explanation as to why these two lightsabers generate the colors they do, nor do they symbolize any particular rank or level. Hopefully, with The Book of Boba Fett now out on Disney Plus and Obi-Wan Kenobi coming soon to the streaming platform, Disney and Lucasfilm will find a way to address that down the line.