Patrick appears at the beginning of the first episode as the test pilot for the AEU's new model, the AEU-09 AEU Enact, and subsequently becomes Exia's opponent as part of Celestial Being's first public armed intervention. He is swiftly defeated in an almost comic fashion, claiming in desperation to be the AEU's "ace", and that he is "special" due to his apparent victory in 2000 simulated battles. As a result of this public humiliation, Patrick vows to defeat the Gundams.

In episode 6, he is sent in with the rest of the AEU's enforcements to aid Moralia in their fight against Celestial Being, where he declares the GN-005 Gundam Virtue, piloted by Tieria Erde, as his target. However, after one single blast from Virtue's main cannon annihilates the surrounding AEU squadron, he manages to retreat after yet again sustaining significant damage.

In preparation for "Project G", a joint military operation between all 3 power blocs, Patrick Colasour meets his captain Kati Mannequin for the first time and - after she punches him twice for being late - claims to have instantly fallen in love with her. Much to Patrick's chagrin, she initially places him on standby for during the first stage of the operation. After sortieing, Patrick targets the battle-worn Virtue once more with the intention of capturing it, but is eventually met with little success after Team Trinity intervene, and is shown crying out for his captain when communication devices are jammed by Throne Drei's red GN particles. In episode 20, Patrick shows up at Kati's house with a bouquet of red roses and asks her out to dinner, to which she accepts.

After all his previous failures, however, Patrick's first victory comes with the aid of his new GN-X, and the driving force of a possible kiss from the captain. When Virtue's system encounters an error when transferring to Sumeragi's back-up system during the UN's assault on the Gundams, Patrick takes advantage of Tieria's immobility and attacks his suit with a beam sabre; however, Lockon Stratos is the one who takes the damage when he uses Dynames as a shield, severely damaging the cockpit. Ironically, this made Patrick the first pilot to cause heavy damage to a Gundam and badly injure a Meister, causing temporary blindness in Lockon's right eye. When Patrick contacts the command center apologizing for letting the Gundams get away, Kati appears to be relieved, saying that she "got all worried".

Patrick is pitted against Tieria (this time piloting the GN-004 Gundam Nadleeh) one last time in the final battle of season one. Although initially overpowered, Nadleeh loses a limb to a timely shot fired by Alejandro Corner in his Alvatore, disabling the Trans-Am system. Patrick and another GN-X fire at Nadleeh until it is reduced to a mere torso, head and arm. Patrick and Tieria fire at each other, and while Patrick succeeds in taking off Nadleeh's head, his own mobile suit suffers huge damage, with the entire top half being blown off.

Patrick was reported as being MIA and widely speculated to be dead until the final episode, in which he can be seen standing behind Sergei and Kati in the Earth Federation's military line-up.

In the side-story manga Mobile Suit Gundam 00F, Fon Spark, from the Fereshte branch of Celestial Being, is shown kicking the bottom half of the suit - with Patrick alive and well - down from orbit.

From the very start, Patrick is portrayed as the typical brash and hot-blooded pilot who thinks irrationally high of himself, his constant defeat making him somewhat of a comic relief. His lack of success in real combat is something he is sensitive about, although that does not stop him from continuously introducing himself as the AEU's greatest pilot, and viewing himself very highly. He also appears to be somewhat of a playboy, although he has since set his sights solely on his commander.

Patrick is known to use less-than-honourable tactics in battle, as seen in his attack on the immobile Virtue. His apparent idiocy and lack of perceptiveness also gets him into trouble often; one key example is when he meets with Daryl Dodge on one of the UN Army's ships, asking to see the Union's ace, Graham Aker. After Daryl tells him that Graham will not be participating in the GN-X operation, Patrick responds by calling him a coward. Enraged, Daryl grabs him by the collar and warns him not to badmouth Graham. Patrick protests, telling him that he is a pacifist, but is saved from possible combat when Kati interrupts them.

During the second season, Patrick joins the A-Laws, not out of support for their policies, but to be closer to Kati Mannequin. At this point, he becomes known as "The Immortal Colasour" since despite the fact he gets shot down in every battle, he has fought with the Gundams more than any other pilot and survived. As Kati continually butts heads with A-Laws commanders over their combat methods, Patrick starts to become an emotional support for her. After the battle of the orbital pillar, Patrick follows Kati as she deserts the A-Laws to join the rebel federation forces. During the final battle with the A-Laws, Patrick's unit appears to be destroyed, protecting Kati's command ship from a suicide mobile suit.