Blue is the most prominent and was used to indicate the user was a Jedi Guardian, a Jedi highly skilled in lightsaber combat. The color itself was said to represent righteousness and bravery, virtues the Jedi stand for, which is why the color is so prevalent and so closely associated with the Jedi.
Right now, there's some very specific colors that a lightsaber can be. There's always the possibility of new colors being added, but as it stands in the official lore, the only colors possible (and what they represent) are the following: Blue - loyalty, stability, truth, justice. Green - growth, safety, harmony.
The Jedi and others who serve the Light Side of the Force are powerful, yes, but there is an innate calmness, a collectedness, a coolness about them. Blue lightsabers are not overly complicated because they don't need to be. They belong to the good guys.
Anakin Skywalker's Lightsaber
There's youngling blood on that blue blade. After being confiscated by Kenobi on Mustafar, this lightsaber is passed onto Anakin's son, Luke, who uses it until his defeat on Cloud City. Somehow, Maz Kanata acquires the saber and yields it to Rey in The Force Awakens.
Skywalker lightsaber. Anakin Skywalker carried this blue-bladed Jedi weapon throughout the Clone Wars. After dueling his former apprentice on Mustafar, Obi-Wan Kenobi took Anakin's lightsaber and kept it on Tatooine for nearly two decades.
A crystal embodies the Jedi as the heart of the lightsaber, and pure kyber has no color until it's bonded to the Force user. This process likely resulted in Rey Skywalker's lightsaber being yellow.
Rey's lightsaber was a yellow-bladed lightsaber that was constructed by the Jedi Rey Skywalker following the First Order-Resistance War.
Originally the weapon had a blue blade, but after his destruction of the Jedi Temple and fall to the dark side in 28 ABY, Ren modified it into one with a red blade.
Leia's lightsaber was a blue-bladed lightsaber used by Princess Leia Organa during her time as a Jedi Padawan training under her brother Jedi Knight Luke Skywalker.
Without a doubt, the most notable Jedi with a purple saber is Mace Windu, portrayed in the prequel trilogy by Samuel L. Jackson. Audiences first got a glimpse of the unusual blade in Episode II: Attack of the Clones, making Windu the coolest Jedi in one cinematic moment.
When Obi-Wan Kenobi's blue saber clashed against Darth Vader's red in the first film, each color was a representation of their innermost selves, a legend which would take further shape and definition as the saga continued. Originally, it was a pretty simple code to crack. Blue was good. Red was evil.
Red lightsabers are the weakest, according to a Star Wars study conducted at the University of Leicester regarding lightsaber colors. Decades of Star Wars lore has dictated that the red lightsabers favored by The Sith offered greater offensive capabilities than the softer colors favored by The Jedi.
Obi-Wan Kenobi's third lightsaber was his new weapon that he created during the Clone Wars upon his promotion to Jedi Master and wielded until his death after his rematch with Darth Vader on the Death Star.
The Darksaber goes back to the time of Tarre Vizsla, the first Mandalorian to become a Jedi Knight. He created a one-of-a-kind lightsaber with a flat blade of dark, swirling energy. In the Star Wars Rebels episode “Trials of the Darksaber,” Fenn Rau shared more of the Mandalorian folklore surrounding the weapon.
In the final moments of The Rise of Skywalker, Rey ignites her new lightsaber and reveals its yellow blade. We don't know where she got that kyber crystal, but her color choice lines up with her being the new guardian of the Jedi traditions.
With the dust settled, Rey goes to Tatooine, to the old moisture farm home of Luke to bury the sabers where they belong. That's when Rey whips out her own lightsaber, a new yellow-bladed sword built out of her signature scavenger staff.
Luke Skywalker's lightsaber was originally pink in the original Star Wars comics. Obi-Wan Kenobi and Darth Vader both used pink lightsabers in their war against each other. Pink lightsabers have a greater frequency in comparison to the other common colors of lightsabers, making them more powerful.
Even though Kylo Ren uses a red lightsaber, harnesses the dark side of the Force, and wears a cape, he is not a Sith. Because of that, he can never hold the title of Darth. Instead, he was just a chaotic mess of the dark side (until he eventually found his way back to the light).
In the earlier part of his life, Anakin wielded the distinctive blue lightsaber of the Jedi. Anakin's blue lightsaber was put to good use in service of the Jedi cause during the Clone Wars. In the latter portion of his life, as the dreaded Darth Vader, he carried the red lightsaber associated with the Sith.
Given that she studied Luke's ancient Jedi texts and was trained by Leia, Rey most likely used a variation of Form VI, Niman. Form VI, Niman, takes elements from the previous five forms and combines them into a pastiche that's proficient in all situations, but lacks the specialization of other forms.
This can be seen in the novel starwars.wikia.com/wiki/Rogue_Planet. It's because of his mastery of sorsue (sorry for my bad spelling.) Well if you want the ACTUAL reason it because in the original 3 films the Green Light Sabre didn't exist until after Obi Wans death.
At the end of the film, Rey returns to Luke's home on Tatooine, where she buries Luke and Leia's lightsabers, then reveals her own—decked out with a golden-yellow blade, a hilt that looks like it might've been crafted from her staff, and a cigarette-lighter-looking switch that turns it on.
Master Yoda has risen above all others to claim the top spot as the most powerful Jedi of all time and the true chosen one according to IGN's audience. He won pretty handily as well, as he was victorious in 89,756 of his 95,243 battles and had a win percentage of 94.2%.