Cal can't unlock or use a red lightsaber in the game; this is because Star Wars Jedi: Fallen Order is a canonical story within the Star Wars universe, and while an RPG may allow players to use a red lightsaber color for fun, that would mean giving Cal the chance to wield a red lightsaber.

Apply your changes, and Cal’s lightsaber will now have the iconic red hue. Unlocking the red lightsaber in Star Wars Jedi: Fallen Order adds an extra layer of customization to Cal’s weapon, allowing players to wield the same color traditionally associated with the Sith and the Dark Side.

Lightsabers are famously the most identifiable weapon in the Star Wars franchise, an "elegant weapon for a more civilized age," according to Obi-Wan Kenobi. In Star Wars Jedi: Fallen Order, players start the game with a lightsaber in their hand, which they use in a brief duel with the Second Sister.

In Star Wars Jedi: Fallen Order, players start the game with a lightsaber in their hand, which they use in a brief duel with the Second Sister. It's possible to unlock the double-bladed lightsaber in Star Wars Jedi: Fallen Order quite early on, heading to the planet Dathomir. But after that, the next best thing is changing the lightsaber color.