The 2026 GMC Sierra HD introduces several improvements over the 2025 Sierra HD, with GM opting to streamline the lineup by removing some rear-wheel-drive model configurations, plus adding new options to match styling. For the final point, the 2026 Sierra HD offers a number of new paint colors. Now, GM Authority take a closer look at the 2026 GMC Sierra HD in new Coastal Dune paint options with this First Look.
The Coastal Dune is marked with color code G42 and touch-up paint number WA-234L, and can be paired with the Sierra HD Pro, SLE, AT4 and AT4X trim levels. Pricing for the new hue is set at $495. While the 2026 GMC Sierra HD SLT, Denali, Denali Ultimate are not available in Coastal Dune paint.
Coastal Dune indirectly replaces Thunderstorm Gray (paint code GNO) on the Sierra HD color palette, which was originally added to the Sierra HD lineup with the launch of the 2024 model year.
Moving to the interior, the Coastal Dune is available along with any of the interior colorways offered for the 2026 Sierra HD Pro, SLE, AT4, and AT4X trims. We have more info on all of the 2026 GMC Sierra HD interior colorways in our previous coverage, so check it out to learn more.
As discussed previously, the 2026 GMC Sierra HD offers a total of nine different paint options, all listed below (relevant color codes are listed in parentheses):
- Red Cardinal (G7C)
- Coastal Dunes (G42)
- Metallic Rain (GXP)
- Glacier White Tricoat (G4J)
- Black Onyx (GBA)
- Sterling Metallic (GXD)
- White Peak (GAZ)
- Titanium Rush Metallic (G6M)
- Volcanic Red Layer (GNT)
As a reminder, the 2026 GMC Sierra HD offers two different powertrains, including a naturally aspirated 6.6L V8 L8T gasoline engine, which produces over 401 horsepower and 464 pound-feet of torque, while the optional 6.6L V8 L5P Duramax turbodiesel produces over 470 horsepower and 975 pound-feet of torque.
A more capable variant of the GM T1 platform provides the bones. Production takes place at the GM Flint Assembly plant, located in Michigan.
SUBSCRIBE TO GM AUTHORITY
We’ll send you an email or two a day with the latest GM news coverage. It’s completely free.
