Disney sources say they use Kyber crystals. Synthetics have yet to be mentioned in Disney-canon. They have yet to mention where the color comes from, ie the force user's meditation or the crystal's natural color. It is suspected that the white sabers Ahsoka uses are linked to her unaffiliated status, which would support her neutral position of light or dark, jedi or sith, influencing the crystal. So, until otherwise shown, I'm leaning to the belief that the meditation of the user makes the color. Legend canon would make the synthetics red, and Kyber crystals would be colored by the user. But, Luke and his new Jedi used many things as crystals with lots of color possibilities in legend canon.
Darth Vader's saber was found, but someone made a point that it was found multiple times in Disney canon. So, characters may just believe it's his. I view it that I don't know what was in the shaft into which it fell. It fell before the Emperor. The Emperor's fall was accompanied by an explosion, but the saber may have fallen into some other path. If Anakin/Luke's saber can be found after falling into some ventilation tube, then Vader's could perhaps have been found by someone evacuating before the Deathstar exploded. Kylo is a collector of Vader memorabilia. He has Vader's helmet. He wants the saber. Maybe he has or will find Vader's saber.
According to the OC, Luke's crystal was synthetic. The green color came of his choice during its creation. (It was actually a decision made in post. LS sabers were all going to be blue, but they needed a color that stood out better against the blue sky over Tatooine. Thus green was born.
) The Empire had made lightsabers illegal (hence why Kanan kept his in 2 pieces, to diminish its saber-esque appearance.
), and had occupied all crystal producing planets. A) He probably wouldn't have known where to go to get one, and B) he would have had to get past the Empire to get one. Although, how he learned to synthesize a crystal I don't know. The Sith typically wouldn't be bothered by coloring a crystal, thusly why Sith sabers are traditionally red. It also added to the practicality of the territories. The Sith Empire lay in the "Unknown Regions" beyond the Republic. Even after their forces collided, it was unlikely that the Sith and Jedi were going to go crystal shopping at the same locations.
"Hey Darth."
"Hey Jed. Whatcha up to?"
"Looking for saber crystal. Gonna kill you with it. You?"
"Same."
It conjures memories of this
If what you say is true, (SPOILER ALERT!) then why wasn't Ezra's new saber turning red while he was using the dark side after finding the Sith holocron?
To the fate of Vader's saber, I sincerely doubt that in the mad scramble to get the hell out of Dodge, anyone is going to happen across it. It most like landed in an unoccupied area and never even seen.
Then this...
If it wasn't destroyed, then it ended up as one of a billion pieces of space debris hopelessly lost in the void. The helmet would have been an easy find. Go to Endor, poke around, "Hey, a melted helmet. Score." Question is, who initially found it, Ren or Snoke? As for the Flex showing up, I firmly believe that was the doing of some jock itch that said "Let's have the Skywalker saber show up with no convincing story. We'll make millions." I mean Abrams ripped off most everything else from Ep.4, why not find the most iconic saber once again being stored in a chest by some old fogie?
But as to the original question of "blade fields" I found this
I like the part about "recently constructed". Looking also at the openings on the primary and quillions, both have similar if not identical constructions. My only worry is that part about "raw power" which suggest that it is in fact bled power and no field. But then that would also suggest that the primary has no field either. This might also go to help explain the unstable appearance of the blades.
In this cutaway, no emitters are indicated. From this we can either conclude that none exist, or that their inclusion is just assumed. Being old-school, I lean toward the assumption of inclusion. I'm inclined to believe that if the blades are simply raw energy, that this saber design would drain its power supply in very short order.
I know nothing of gundam....
Gundam is an anime franchise that kicked up 2 years after SW. One of the legacy weapon technologies that spans the various series is an energy weapon known as a beam saber.
The only real difference is that it is scaled to the size of a 50' tall battle mech. Awesome.
I remember quite distinctly. Because I had at first thought that Rey had cut his hand off thus continuing the ongoing 'in every movie someone gets a hand cut off at least once' theme that has been going on through the first 6 movies. But on closer inspection, it was just the saber falling to the ground in 2 pieces. It's on the Blu Ray movie. At about 1:57:30, they are grappling, her left holding his right wrist and vice versa. She has his blade tip down in the snow. Then she gets her right hand free of his as he's holding it and slashes through the hilt of his saber.
If you play it in slow motion, you can see part of the saber go flying off. Then the next shot that we see him, laying on the ground, it's obscured by snow but it looks like his saber is laying there beside him missing the emitter.
I hate to bust on your "theme", but nobody lost hands in episodes 1 & 4.
I Googled "did kylo ren lose his hand". The result is as follows:
According to the script, Kylo Ren didn't lose his hand. He got struck in the face and chest only. ... HE GOES DOWN, SUDDENLY A FEARFUL MAN, A LARGE BURN SCAR SLASHED ACROSS HIS FACE! He still reaches for his saber.