I HATE THOSE DIRTY BLUES

Sarge
Sarge is the Colonel (formerly Staff Sergeant) and leader of the Blood Gulch Red Team. He is a military man with a Southern United States accent and is the only Blood Gulch soldier on either team consistently serious about the Red vs. Blue civil war. His sociopathic battle plans and irrational behavior often entail the constant danger of his own men, mostly Grif. His armor color is red.

Grif
Grif is habitually lazy, irresponsible, arrogant, foul-mouthed, and pessimistic. He spends most of his time senselessly talking to and arguing with Simmons. Otherwise, he enjoys eating and sleeping. These characteristics earn him the disrespect and ridicule of both Sarge and Simmons. Sarge in particular greatly resents Grif for his laziness. Grif is arguably the most incompetent soldier of both teams, a trait that he acknowledges and takes a twisted sense of pride to. Despite this, he does seem to have some skill at driving/piloting vehicles and is usually the one to do so. His armor color is orange.

Simmons
Simmons is a hard working, socially awkward soldier who is often seen sucking up to Sarge, presumably due to the lack of a father figure in his early life. Despite this, he still has expressed some disdain towards him, usually for his inept military tactics. Simmons is shown to be one of the few smart characters of the Blood Gulch soldiers and arguably the most level-headed, though his erratic outbursts do sometimes contrast this. His intelligence has led to him being branded as a "nerd", mostly by Grif. Simmons and Grif are often seen together, either chatting or bickering. His armor color is maroon.

Donut
Donut is the eager rookie who tends to annoy his teammates with his naïve, garrulous, and cheerful nature and has become more effeminate and childish as the series progresses. Although usually overlooked by most characters, these qualities have led some to suggest that he is homosexual. Despite this, Donut is seen to be quite a skilled soldier, having an excellent arm, with the most notable example being "killing" agent Tex with a plasma grenade thrown halfway across Blood Gulch. His armor color is pink (though he claims it is light-ish red).

Lopez
Lopez is a robot mechanic built by Sarge, in which he got a voice box programmed to only speak Spanish. Due to this, none of the others can understand him, although Donut claims to be able to understand him. Lopez is also, like Simmons, one of the few level-headed and rational members of the Blood Gulch soldiers, though he easily becomes irritated by the Reds' antics and their constant misinterpretation of what he is trying to say. His armor color is brown.

Glory, Glory to the Red Team!
Red Vs. Blue Song #4 'Sarge's Blues'
Sarge VS Church! [RAP BATTLE]