Based on the GMT355 platform, the Colorado was introduced in 2004. It is available in three models: Regular Cab, Extended Cab, and Crew Cab.

The Regular Cab is available in six trims: 1LS, 1LT, 2LT, 3LT, Work Truck, and Chassis Cab. The Extended Cab is available in five trims: 1LS, 1LT, 2LT, 3LT, and Work Truck. The Crew Cab is available in three trims: 1LT, 2LT, and 3LT.

The Colorado comes with a powertrain warranty for five years or 100,000 miles. It contends with other pickup trucks such as Isuzu i-Series, Chevrolet LUV, Holden Rodeo, Isuzu Rodeo, Isuzu D-Max, and Hummer H3.

The 2LT and 3LT trims derive power from a Vortec 3.7-liter Inline-5 engine, which churns out 242 hp @ 5,600 rpm and 242 lb-ft. @ 4,600 rpm. These trims are linked to a standard Hydra-Matic four-speed automatic transmission, which is optional on the 1LS and 1LT trims. The 1LT models are also available with the option of a Vortec 3.7-liter Inline-5 engine.

Both the types of engines feature Double Overhead Camshaft (DOHC). Maximum engine speed for both the engines is 6,300 rpm.

The front fascia of all Colorado trims looks distinct with an attractive, bold chrome crossbar grille and multi-lens high-intensity headlamps, composite with flash-to-pass feature. All Colorado trims come standard with a Dark Smoke Gray front fascia. The 3LT features a standard body-color front fascia, including body-color bumpers, available as optional on others trims.

All trims feature standard front and rear chrome bumpers, an air dam, and Daytime Running Lamps, which include Automatic Exterior Lamp Control. Halogen fog lamps are standard on the 3LT and optional on the rest of the trims.

Two-side galvanized steel body panels are a standard feature for all Colorado models. Dark Smoke Gray body-side moldings are standard on the 2LT and 3LT, and optional on 1LS and 1LT trim levels. The Colorado also features wheel flares, which add to its rugged looks and also help protect its body from road debris.

The 1LS and 1LT trims feature manual fold-away mirrors, while the 2LT and 3LT trims come with power, fold-away mirrors. The 2LT and 3LT trims feature standard solar-ray deep-tinted glass on all windows, except for the windshield and driver plus front passenger-side windows, which come with light-tinted glass. Solar-ray deep-tinted glass is optional on the 1LS and 1LT trim levels. A rear, sliding window is standard on the 3LT and optional on rest of the trims.

The Colorado also features a removable and lockable tail-gate, which can be set in two positions. It can be fully closed or opened at 55-degree, as well as lowered to a flat horizontal position. All trims come standard with rear doors. All Extended Cab models have two rear-openings, rear-hinged doors that offer easy access to items kept inside the cab. The Crew Cab models have two full-opening, front-hinged doors, which make it easier to get in and out of the rear area.

The Regular Cab and Extended Cab models feature a 72.8-inch long cargo box, while the Crew Cab models come standard with a cargo box that is 61.1 inches long. The cargo box features two separate tiers, which you can use to load large amounts of cargo in layers. It also comes with six tie-downs, which make it easy to secure any equipment, tools, or gear. In addition, the Colorado pickup box offers massive cargo volume.

The 1LS models wear standard 15-inch steel wheels and roll on P205/75R-15 all-season, Blackwall tires. The 1LT and 2LT models come with 15-inch aluminum wheels and ride on 15-inch all-season, Blackwall tires. The 3LT models feature standard 15-inch chrome aluminum wheels and 15-inch all-season, Blackwall tires.

Some exterior option packages available on the Colorado are the Sport Appearance Package, the Xtreme Appearance Package, and the Street Pak.

The 1LS Regular Cab and Extended Cab models come standard with LS Cloth-trimmed seats. These models feature three-passenger 60/40 split-bench front seat, integral outboard head restraints, and dual cup holders.

The 1LT Regular Cab and Extended Cab models feature standard Deluxe Cloth-trimmed seats. These models come with three-passenger 60/40 split-bench front seat, integral outboard head restraints, manual recliners, and center armrest with storage and dual cup holders. This seating is optional on the 2LT Regular Cab and Extended Cab models.

The 2LT and 3LT Regular Cab and Extended Cab models come standard with Deluxe Cloth-trimmed seats. These models feature standard high-back front bucket seats, integral head restraints, manual recliners, and floor-mounted center console with storage and dual cup holders. This seating is optional on 1LT Regular Cab and Extended Cab models.

The 3LT Extended Cab models are also available with the option of Deluxe Leather-trimmed seats. Also optional are leather-appointed front bucket seats, vinyl rear seats, heated front seatbacks and cushions, eight-way power-adjustable driver seat with power lumbar, six-way power-adjustable passenger seat, adjustable head restraints, recliners, and floor-mounted center console with storage and dual cup holders.

Two forward-facing rear seats, including under-seat storage compartment, are standard on all LT Extended Cab models, and optional on 1LS Regular Cab and Extended Cab models.

The 1LT, 2LT, and 3LT Crew Cab models come standard with Deluxe Cloth-trimmed seats. The 1LT models feature three-passenger 60/40 split-bench front seat, integral outboard head restraints, manual recliners, and center armrest with storage and dual cup holders. However, the 2LT and 3LT Crew Cab models include high-back front bucket seats, integral head restraints, manual recliners, and floor-mounted center console with storage and dual cup holders.

The 3LT Crew Cab models are offered with optional Deluxe Leather-trimmed seats. These models are available with the option of high-back front bucket leather-appointed front seats, leather-appointed rear seats, heated front seatbacks and cushions, eight-way power-adjustable driver seat with power lumbar, six-way power-adjustable passenger seat, adjustable head restraints, recliners, and floor-mounted center console with storage and dual cup holders. Rear bench seat with integral outboard head restraints is standard on all Crew Cab models.

All Colorado trims come standard with front, manual air conditioning. All trims, with the exception of 1LS, come standard with a leather-wrapped steering wheel. A tiltable steering column is standard on all trims.

The Colorado comes with analog instrumentation, which includes speedometer, tachometer, odometer with trip odometer, and an indicator each for fuel level, engine temperature, and Driver Information Center (DIC), which continuously monitors and reports on numerous vehicle functions.

The 1LS, 1LT models feature a prismatic rear-view mirror, while the 2LT models come with manual day/night rear-view mirror. The 3LT models, however, come with more convenient auto-dimming mirrors with eight-point compass and outside temperature indicator.

Two 12 volt auxiliary power outlets are present on all Colorado trims. A sliding rear window is standard on the 3LT models and optional on other trims. All LT models are available with the option of a power sunroof, which allows you to enjoy an open-air driving experience. All Regular and Extended Cab models come with a 44-cubic feet cargo box, while the Crew Cab models come with a 37-cubic feet cargo box.

For entertainment, the 1LS models feature a standard AM/FM stereo, while all LT models come standard with an AM/FM stereo with CD/MP3 player, seek-scan, auto-tone control, Radio Data System (RDS), automatic volume, and TheftLock. This audio system is optional on the 1LS models. The LT models are also available with the option of an AM/FM stereo with RDS, 2 in-dash six-disc CD changer, automatic volume, and an auto tone control. Also optional on the LT models is an XM Satellite Radio, which requires AM/FM stereo with CD/MP3 player.

The 2WD models and 4WD models of Colorado can handle a maximum payload of 1,547 pounds and 1,535 pounds respectively. The Regular Cab and Extended Cab models can tow up to 2,300 pounds and 2,100 pounds, in that order.

Some optional packages available on the Colorado are Sun and Fun Package, Sun and Sound Package, Power Convenience Package, and Comfort Convenience Package.

The Colorado is directed by a power-assisted rack-and-pinion steering, which offers precise and direct maneuvers.

The Colorado rides on independent front suspension with coil springs and conventional stamped A-arms. Also included are a front stabilizer bar, twin-tube shock absorbers, and rubber jounce bumpers, and two-stage multi-leaf rear springs. This suspension system is tuned for a smooth and firm ride.

The Colorado is equipped with front disc and rear drum brakes, which are sharp and powerful, and bring the Colorado to an instant halt, as soon as the brake pedal is pushed. The brakes are also easy to modulate for jerk-free stops. The Colorado also comes with four-wheel antilock brakes, which help the driver maintain steering control in an emergency braking situation.

Automatic locking rear differential is optional on all trims. It allows additional low-speed traction on snow, mud, or ice. If the system determines one rear wheel is spinning faster than the other, the axle locks within a fraction of a second so that both wheels turn together to provide the traction necessary to move the vehicle forward. All trims feature standard cruise control, while the option of traction control is limited to 2WD trims.

The Avalanche features four-wheel disc brakes, which supply forceful stopping power to its wheels and bring it to an instant halt. It also comes with a four-wheel anti-lock braking system (ABS), which prevents locking up of wheels during sudden braking or emergency maneuvers.

The 4WD models of the Colorado also come with the option of an Insta-Trac electronic shift transfer case, which includes dash-mounted controls. With Insta-Trac, you can shift from 2WD to 4WD and back with just the touch of a button. There are three drive settings to choose from; 2HI, for driving on most streets and highways; 4HI, which engages the front axle to help drive your vehicle, and can be used when you need extra traction; and 4LO, which engages the front axle to provide extra traction. 4LO sends maximum power to all four wheels.

The Colorado offers responsive steering and a smooth ride, but its large turning radius poses a problem while driving or parking in tight spots.

It also features standard dual-stage frontal airbags with a Passenger Sensing System. Driver and right-front passenger dual-stage front air bags are designed to supplement the safety belt system in the event of a frontal collision. They sense the severity of a crash, determine if the airbags should be deployed, and to what extent should they be inflated. The Passenger Sensing System automatically switches off the right-front passenger airbag on the basis of the passenger's weight and the type of pressure put on the seat.

Some more standard safety features include child security rear door locks and the LATCH (Lower Anchors and Top tethers for Children) system for child safety seats.

The Colorado also features an Anti-lock Braking System (ABS), which is a crash avoidance feature. It helps prevent locking up of wheels during braking in slippery road conditions. Also standard on the Colorado is traction control, which utilizes electronic controls to help reduce rear-wheel spin, while driving on dicey surfaces.