By now, you've definitely seen the trailer for The Last Jedi, and one of the major reveals was the color of Rey's lightsaber. Sure, we got a tease of it with the leaked Star Wars: Battlefront II art, but we now have official confirmation that her saber is blue. On the poster, her saber is blue where she's holding it and red up toward the top.
But that's clearly just some clever poster art. In the trailer we see Rey wielding a perfectly blue saber.
Sadly, Rey's saber does not appear to be a dual-bladed one. That would have been awesome.
Some of you might be reading this thinking, why does the color have anything to do with, well, anything?
Those into the Star Wars Expanded Universe might know this, but there used to be a rule for lightsaber crystal colors, back in the old Jedi days. From the StarWars wiki: Blue indicated a Jedi Guardian, a Jedi who used the Force on a more physical level. Green indicated a Jedi Consular, a Jedi who preferred to reflect on the mysteries of the Force and fight the dark side at its heart. Yellow indicated a Jedi Sentinel, a Jedi who honed his or her skills in a balance of combat and scholarly pursuits.
Now, according to previous Star Wars canon, those color distinctions have mostly fallen out of favor. But there are still some notable distinctions.
We all know that a red saber is short-hand for those on the dark side of the force. Emperor Palpatine, Darth Vader, Darth Maul, Kylo Ren – they all used red sabers.
But the Skywalkers both used blue sabers. While Anakin used a green saber while first training, then transitioned to a blue saber once he lost his green saber. He then wields that blue saber even as Darth Vader, until his duel with Obi Wan Kenobi. And Luke, well, we all know Luke used a blue saber until he lost it, along with his hand. It's the same saber Rey picked up in Force Awakens. So, Rey using a blue saber, pretty much just fuels the "is Rey a Skywalker" debate. Because she could be.
What is much more interesting than Rey's parentage though, is that both Luke and Anakin both wielded blue and green sabers. After losing his blue saber, Luke ends up using a green saber in Return of the Jedi, where his role is a bit more than just that of a combat Jedi. Luke in Return is much more of a mature Jedi, one who understands the Force on a level deeper than just the physical. Much like the original Jedi Sentinels, Luke in Return of the Jedi represents a balance of combat and wisdom.
Meanwhile, Anakin turns from a dutiful student, studying both the physical and mental aspects of the foce, to a Jedi Guardian during the Clone Wars.
Yoda, every time we see him, had a green saber. Because of course the grand master would be a Jedi Sentinel.
Sure, this color meanings of the lightsaber crystals deal was never directly addressed in the films, and in fact started in the games, then later the Expanded Universe books, but they had to get it from somewhere. But it really does seem to hold up to what we've seen.
As long as you discount Mace Windu, because Samuel L. Jackson does what he wants.
So seeing Rey wield a blue saber makes sense. Like Luke in A New Hope, Rey is just learning the ways of the force and connects to it on a mostly physical level. And it might actually be Luke's original saber, meaning it's been wielded by perhaps three generations of Skywalkers.
Of course, this could all be mindless speculation since the current Star Wars films aren't holding to the established Expanded Universe canon.