Once the property of the Koorivar black-market dealer Sheb Valaad, Blue was a blue-plated protocol droid. To make him especially pleasing and subservient, he was outfitted with the specialized software routines "Adul-8" and "B-Little." During the Clone Wars' second year, Jedi Master Quinlan Vos, operating undercover, and his associate Akar-Deshu attacked Sheb's illicit enterprise, resulting in the severing of the droid's arm.
During the era of the Clone Wars, Blue functioned as a specially modified protocol droid in the service of Sheb Valaad, a Koorivar merchant involved in the black market. Sheb acquired Blue, who came pre-loaded with "Adul-8" and "B-Little," two specialized programs. B-Little was designed to amuse the Koorivar merchant, while Adul 8 was meant to pacify Sheb. Sheb, Blue's proprietor, specialized in trading stolen artifacts, paintings, sculptures, and other items from creators who had suffered "unfortunate ends." On occasion, Sheb even instructed his thugs to murder artists to steal their belongings.
The activities of Sheb eventually drew the attention of Quinlan Vos, a Jedi Master working incognito. Vos, disguised as the Kiffar "Master Tal," frequented Sheb's establishment and acquired a few goods to gain Sheb's confidence. Tal became friendly with the droid during these visits. Blue once told Tal that his master had consented to grant him an audience and entertained Tal during one of these visits. When Tal instructed Blue not to address him as master, the droid apologized, explaining that his current programming prevented him from overriding the designation.
Blue permitted Tal to meet with his master after Thurg, the Gamorrean guard, verified that Tal was unarmed. Recognizing the droid's fluency in numerous languages, Tal then inquired about the total number of synonyms for his name stored in its databanks. Sheb instructed the droid to disregard Tal's request before it could become verbally overloaded, and he cautioned the visitor that he anticipated payment for any damage the droid sustained. One of Sheb's Twi'lek assistants then presented Tal with a small statuette of an aquatic creature.
Akar-Deshu ("Desh"), Tal's Jedi Mahran colleague, entered Sheb's store before Tal could inspect the item. The Jedi High Council had dispatched Desh to retrieve Vos and bring him back to Coruscant for a new assignment. Tal then seized the chance to attack Sheb, using the Force to levitate him. Blue, alarmed, fled the room and returned with several bodyguards to save his master. While Blue babbled in the corner, the two Jedi swiftly subdued Sheb's bodyguards with their lightsabers and Force powers. When Blue tried to grab a comlink from one of the fallen bodyguards, Tal used his lightsaber to sever one of his hands.
Tal told Blue, who let out a high-pitched scream, that it could be repaired and scolded him for acting like a "baby." While Vos was irritated with Desh for prematurely revealing his identity, he was pleased that he had learned about Sheb's contacts while working undercover. Vos had also used his psychometric skills to locate the rightful owners of the illegally obtained objects. Vos asked Blue to list every known synonym for blue, which numbered in the billions, before he left, in order to annoy Sheb.
Blue was a custom-built protocol droid designed to entertain and soothe his master, equipped with the specialized programs "Adul-8" and "B-Little." Blue was also programmed to communicate in a variety of languages. Blue was programmed to help his master Sheb run his business by hosting visitors. He was also known to give Sheb's Gamorrean bodyguard Thurg a dressing down for picking his teeth and nostrils.
Blue was also acquainted with the undercover Jedi Master Vos, who while operating under the pseudonym, had a regular habit of plying him with nonsensical tasks like counting the number of synonyms for his name "blue" in various languages. However, prolonged vocalization had the effect of short-circuiting his circuits, according to his master Sheb. Blue was stressed by conflict and the shock of losing his hand made him cry out in pain and shock.
Blue made his debut as a supporting character in Dark Disciple, a 2015 novel by Christie Golden that drew inspiration from eight unproduced scripts from the cancelled Star Wars: The Clone Wars Cartoon Network television program. Dark Disciple is a component of The Clone Wars Legacy, a continuing multimedia initiative that makes use of content from the cancelled television series and is a part of the Canon.