Chevrolet Colorado Turn Signal Bulb Size

Additional Notes

• The front turn signal on the Chevrolet Colorado uses three distinct bulb types across its production span: the 3757NA for 2004-2012, the 7443NA for 2015-2018, and the 7444NA for 2019-2023.
• The 7443NA and 7444NA are both T20 dual-filament wedge bulbs rated at 12V with a 21W/5W filament configuration, meaning the higher-wattage filament serves the turn signal function while the lower-wattage filament serves a secondary running light function.
• Despite sharing the same T20 form factor and identical wattage ratings, the 7443NA and 7444NA are not the same bulb. The 7444NA designation indicates a revised or updated specification within the same bulb family, and substituting one for the other without confirming compatibility is not advised.
• The 3757NA is a T25 wedge bulb, which is physically larger than the T20 format used in later Colorado model years. The two form factors are not interchangeable, and a T20 bulb cannot be used in a T25 socket.
• All front turn signal bulbs specified for the Colorado carry the "NA" suffix, which denotes natural amber glass. This coloring is built into the glass envelope itself rather than applied as a coating, producing the amber turn signal output without relying on a colored lens.
• The rear turn signal on the Chevrolet Colorado also transitions between two bulb types: the 3057 for 2004-2012 and the 7443 for 2015-2020.
• The 3057 is a T25 dual-filament wedge bulb rated at 12V with a 27W/7W filament configuration, giving it higher wattage output than the 7443, which operates at 21W/5W in the same dual-filament arrangement.
• Neither the 3057 nor the 7443 rear turn signal bulbs carry the "NA" amber glass designation, indicating that amber output in the rear turn signal housings for those years is produced by the lens rather than the bulb itself.
• All bulb types listed across both front and rear turn signal positions conform to ANSI standards applicable in both the United States and Canada, placing them within a standardized North American fitment system.
• A gap exists in the data between the 2012 and 2015 model years for both front and rear turn signals, with 2013 and 2014 absent from the specifications. No bulb size information for those years is reflected in the provided data.