Color
The lightsaber blade was originally going to be white (not a very coherent color), but the decision to contrast the colors of Darth Vader’s and Obi-Wan’s lightsaber blades was made in post-production of Star Wars. In post-production of Return of the Jedi the blue skies of “Tatooine” required another contrasting color. The Prequels and other additions to Star Wars lore have introduced numerous colors beyond blue, red, and green.
According to Star Wars lore the color of the lightsaber blade is determined by the sort of crystals used in the handle. The lore is pretty consistent on that point. However, since the blades are supposed to be plasma in current lore, I like to think that the composition of the plasma is mostly what determines the color. Maybe Luke Skywalker’s lightsaber in Return of the Jedi had a boron plasma blade. :coolsmirk: