"Why Isn't The Death Star's Laser Red?"
Surprisingly, I have only heard this question once. When the Ahsoka novel came out we got a change of canon. Sith crystals are no longer synthetic but regular crystals that have been bent to the will of the dark side user in a process called "making the crystal bleed". That's how we get the red Sith color. In Rogue One we definitively found out that the Death Star uses kyber crystals to power its superbeam. We see them being carried away.
Since we now know that crystals used against their will, one observant friend asked me the question "if crystals that aren't with their owner are red, why isn't the Death Star's beam red?"
Good question.
The only answer I have is; there are different kinds of kyber crystals. There are the crystals used for lightsabers that gives them their color. There are focusing crystals that go inside of a lightsaber as well that help to focus the energy through the colored crystal. There are also crystals that hold information and go inside holocrons to be read. (If you'd like to go in depth about crystals, check out this post.)
My guess is the crystal inside of the Death Star are not the crystals chosen by a padawan on Ilum in the crystal cave. Ilum was destroyed only a year after Order 66. The crystal caves were smashed and covered to prevent future Force-users from getting their crystals there. The crystals used in the Death Star are probably just focusing crystals. These would be crystals used to focus the energy fro the superbeam just like they would focus a lightsaber, just on a much larger scale. That's probably why you see so many large boxes being transported out of the temple on Jedha and not a couple of small boxes.
If the crystals used in the Death Star are in fact supposed to be crystals like those that call to a Jedi for their lightsaber, then the new canon loses water. It wouldn't make sense and contradicts the fact that the beam is green.
So why is the beam green? Probably because that's what color Lucas decided to go with at the time. Remember, blasters have colors. Just like our hand held lasers, it depends on the frequency of the light used. Blasters and lightsabers alike burn on contact. The frequency in the superbeam must be such that it emits a green beam.
So that's it. That's the only answer I had. Agree? Disagree? Let me know @ForceKnowledge!
