The blue lightsaber of Barriss Offee was the uniquely colored blue lightsaber that Barriss Offee used as her personal weapon during the Clone Wars conflict.
The construction of Barriss Offee's lightsaber involved a metallic handle, complete with an end cap at the pommel and a ringed structure at the emitter. From this emitter, the blue plasma blade would be projected upon activation. The hilt also featured several noticeable dials and buttons. These controls allowed Offee to adjust the blade's activation and power levels without compromising her grip during combat. As Offee succumbed to the influence of the dark side of the Force, she eventually favored fighting with Asajj Ventress's red lightsabers, feeling they were more appropriate for her new path.
During the First Battle of Geonosis, Offee made use of her lightsaber. Despite her initial reluctance to participate in the Clone Wars for a time, Offee ultimately returned to the battlefield, wielding her lightsaber during the Second Battle of Geonosis. Furthermore, she employed her lightsaber in the subsequent skirmish aboard TB-73, where she infamously killed clone trooper Trap by impaling him through the abdomen to prevent infection from a brain worm.
Until her descent into darkness in 19 BBY, Offee continued to wield her blue lightsaber. This descent culminated in the bombing of the Jedi Temple, for which she falsely implicated her close associate, Ahsoka Tano. When Tano's mentor, Anakin Skywalker, uncovered Offee's involvement, he sought her out in her Temple quarters. There, he feigned casual interest in her lightsaber, examining it while questioning her, before suddenly activating it and attacking. This prompted Barriss to defensively summon Asajj Ventress's lightsabers, revealing her treachery. Skywalker then engaged her in a duel throughout the Temple, and even outside on a ledge overlooking the training grounds, using her own weapon alongside his own. During the fight, Offee knocked Skywalker down towards the ground before leaping down to attack him, dislodging her former Jedi lightsaber from his grip.