There isn't a canonical Jedi with a natural rainbow lightsaber, but you can get a rainbow-changing "Party Lightsaber" in the game Star Wars Jedi: Survivor after completing the game and starting New Game+; also, in Star Wars Legends, the rare Rainbow Gems, which glow with multiple colors, could be used as lightsaber crystals, with Princess Tenel Ka Djo using them in her saber.
Form VII (Juyo/Vaapad)
Considered the most aggressive and unpredictable disciplines and therefore the most controversial, it was a combat style with a history of the Jedi High Council of the Jedi Order forbidding it and later allowing only select users to practice the disciplines.
Tràkata is a rare and cunning lightsaber technique built on deception and misdirection. Jedi like Kao Cen Darach and Cal Kestis used it to gain surprise advantages in battle, while Sith like Qimir mastered its lethal precision.
The rarest lightsaber color is generally considered black, embodied by the unique Mandalorian weapon known as the Darksaber, with only one ever created, though white (from purified red crystals) and purple (like Mace Windu's) are also exceptionally rare in canon, signifying unique Force attunements or powerful skills. Other rare shades include cyan, gold, and sometimes pink, depending on the specific canon or Legends source.
In Star Wars lore, Order 37 was a grim Clone Trooper contingency plan to capture a wanted individual (often a Jedi) by taking a civilian population hostage, locking down the area, and threatening mass execution if the target wasn't surrendered, making it a horrific tactic used by the Empire to force Jedi compliance. It was considered more brutal than Order 66 because it targeted civilians directly, forcing Jedi to often turn themselves in to save innocent lives, as seen on planets like Bellassa.
In conclusion, Form VII, also known as Juyo or Vaapad, is undeniably the most aggressive lightsaber style in the galaxy. Jedi Master Mace Windu's mastery of this form exemplifies its power and its dangers.
Form VII (Juyo), the "Ferocity Form," was banned by the Jedi Order because it required channeling aggression, anger, and other intense emotions to fuel its wild, relentless, and unpredictable attacks, which closely skirts the dark side and risks corrupting the user, a direct violation of the Jedi Code's emphasis on peace and emotional control, even though Mace Windu later adapted it into the controlled Vaapad variant for a select few.
Adi Gallia – Senior Member of the Jedi Council
Adi Gallia was a prominent member of the Jedi High Council. As one of the few female Jedi Masters on the Council during the final years of the Republic, Gallia played a central role in crucial decisions in the run-up to the Clone Wars.
Through the Force, Yoda was considered to have mastered Form IV to its highest level. He used it in almost all of his battles, and his mastery of the style caused others to describe him as virtually unstoppable against most opponents, including Separatist battle droids, despite his small size and advanced age.
Vernestra "Vern" Rwoh.
While not a common color, among the few characters known to wield a cyan lightsaber, Cal Kestis stands out as the most prominent. Originally wielding a blue blade as a Padawan under Jaro Tapal, Cal's lightsaber underwent significant modifications after his master's demise.
Jedi Battlemaster Cin Drallig and Grand Master Yoda had knowledge and mastery of all seven forms, including Juyo, befitting Drallig's role as lightsaber combat instructor at the Jedi Temple and Yoda's reputation of having mastered all forms of lightsaber combat as did Anoon Bondara, another lightsaber instructor.
The clone commando RC-1136, known as Darman Skirata, got Jedi Knight Etain Tur-Mukan pregnant during the Clone Wars, resulting in their son, Venku Skirata, a Force-sensitive child born outside the Jedi Code's restrictions. Their forbidden relationship and child's birth were detailed in the Republic Commando novels, highlighting the complexities of clone troopers' development and the strictures of the Jedi Order, as Etain was killed shortly after Order 66 while protecting her family.
Order 66, also known as Clone Protocol 66, Protocol 66, or simply "the Order," was one of top-secret contingency orders that identified all Jedi as traitors to the Galactic Republic and, therefore, subject to summary execution by the Grand Army of the Republic.
BACKGROUND INFO: What is Order 69? Order 69(AKA "clean up") was the idea to kill the entire clone army in one sitting, leaving the Jedi defenseless and exposed by the sudden departure.
Anakin Skywalker was a known user of Djem So, both during his initial stint as a Jedi and later when he subsequently fell to the Sith. The Shien variant of Form V allowed the utilization of an unconventional reverse grip, which Ahsoka Tano was known to prefer and use during battles.
A lightsaber can cut through the Vibranium shield if the Jedis have enough time to slowly cut it down. This is highly unlikely if a duel between Luke and Captain America occurs. Captain America will not give him enough time to cut through the shield.
Yoda's original green lightsaber was lost long before his death, falling into the hands of Grand Vizier Mas Amedda after Yoda's battle with Darth Sidious. Amedda used the weapon in a public display, tossing it into a furnace alongside other Jedi lightsabers to symbolize the eradication of the Order.