In the construction of a Sith lightsaber, individuals partook in a process known as bleeding. By ways of the Force, they would pour negative emotions such as rage, hate, fear and pain into kyber crystals. The process would result in the crystals gaining a distinctive crimson or red hue.
There has been a handful of Sith who did not wield a red lightsaber. The most notable case of a Sith using a non-red lightsaber is none other than our true guerilla, Anakin Skywalker. He had a blue lightsaber, which he used in his epic battle against Obi-Wan Kenobi.
A blue-bladed lightsaber belonged to the Sith Master Darth Sidious after his resurrection on Byss.
All the Sith from the Republic that existed between the end of the Great Hyperspace War and the beginning of the Jedi Civil War (5000 BBY - 3960 BBY) did NOT use red synthetic crystals in their lightsabers.
Unlike the Jedi, who wielded various colored lightsabers, the Sith all carried red lightsabers. It was a symbol of their unity and unwavering dedication to the Dark side of the Force. Lightsaber color shares a strong affinity with the identity of the user.
Vader eventually killed the Jedi Master and retrieved his green-bladed lightsaber. He headed to Mustafar, where he bled the saber's crystal, turning it from green to red.
In both canon and Legends, Jedi will sometimes use red-bladed lightsabers in emergencies where they're missing their lightsabers and a Sith weapon is the only one available. Some Jedi are explicitly shown using red lightsabers in Legends, however.
In the Sith Empire, as time progressed pure-blooded Sith were steadily bred out, resulting in only a few pure-blooded Sith left in the Sith Empire by the time of the Great Hyperspace War (5000 BBY). By 44 ABY, the true Sith species in the Empire were believed to have gone extinct due to the interbreeding process.
He is known for carrying a blue lightsaber, but there is one canonical instance of Obi-Wan using a red lightsaber. In the season four finale of the 2008 animated series “Star Wars: The Clone Wars,” titled “Revenge,” Maul and Savage Opress overpower Kenobi and…
Undermined by constant infighting and ruined by the last war against the Jedi, the Sith were rendered all but extinct with the exception of one; Darth Bane survived the ancient order's destruction and passed his knowledge to a single apprentice, Darth Zannah, before being entombed on Korriban, which became known as ...
Light Sith or light-sided Sith were adherents of Sith teachings that rejected the dark side of the Force in favor of the light while retaining their devotion to the Sith as an organization.
Purple. Only one person in canon wields a purple blade: the Jedi Council's Mace Windu. He uses it to decapitate the deadly bounty hunter Jango Fett in Attack of the Clones and to deflect Darth Sidious' Force Lightning with it -- disfiguring his face -- in Revenge of the Sith.
Force lightning almost always required a living conduit for the energy to be channeled; thus Darth Vader, despite being an immensely powerful Sith Lord, was never able to properly employ this ability, as any attempt to generate it carried the risk of shorting out his life support systems.
As the first Dark Lord of the Sith, Ajunta Pall founded the first Sith Empire and expanded it onto other worlds. The Sith took over the planet Ziost and created it as their capital and as Pall's new home. Pall eventually died after serving the Empire for many decades, but his Empire lived on.
As a Sith, Praven was very strong in the dark side of the Force, though he felt stronger with the light side as a Jedi. He wielded a single red-bladed lightsaber as both a Sith and a Jedi, and he was skilled in the use of a wide variety of Force powers, including Force lightning, Force blasts, and Force paralysis.
It's possible that Rey adopted the yellow-bladed lightsaber (or perhaps the kyber crystal conjured a yellow blade based on the changes within its wielder) in honor of those emotionally detached sentinels tasked with guarding the Jedi Order.
Luke Skywalker's lightsaber was changed from blue to green when they were filming because it was difficult to see. This became apparent during act one of Return of the Jedi when the battle on Jabba the Hutt's sail barge was shot during the day. The blue lightsaber blended in with the clear blue sky.
The first known Sith to brandish a red-bladed saber was Karness Muur, a Knight of the Jedi Order who crumbled to his lust for power and became a Dark Jedi.
Many throughout Sith history saw themselves, or were viewed, as this chosen one of legend: King Adas, Darth Andeddu, Darth Revan, Darth Malak, Darth Malgus, Darth Ruin, Darth Bane, Darth Tenebrous, Darth Plagueis, and Darth Sidious.
The average lifespan for a Sith, without any assistance from medical technology, is around 250 years. Taking into account that Force sensitive beings have extended lifespans, most Sith can reach up to 400 years.
The Sith stayed in hiding for a thousand years, their survival unknown to the Jedi, as they continued their revenge against the Jedi through Bane's Grand Plan. With Sith teachings passed down by Bane's Rule of Two, the Order managed to survive.
Jedi were forbidden from taking a political appointment. They were taught that their loyalty was to be to the Force, the Jedi Order, the Republic and to themselves, in that order. Nor they allowed to accept gifts - the latter did not include the traditional Padawan gift, given to the students by their Masters.
Ahsoka Tano, the former Jedi Padawan who aided in the rebellion against the Galactic Empire, is acknowledged as the sole possessor of the white lightsaber.
During his brief apprenticeship under the reborn Palpatine, Luke was forced to replace his green crystal with a red Sith gem. He ultimately wielded this red blade in rebellion against Palpatine, who had a blue-bladed lightsaber and overcame the Sith Lord. Luke afterwards changed back to his crystal.