2018 GMC Sierra 1500 Paint Color Codes & Touch-Up Guide

Whether you are fixing a small rock chip from the highway, repairing a deep scratch on your tailgate, or color-matching aftermarket accessories, finding the exact paint color for your 2018 GMC Sierra 1500 is the first and most critical step. Using the correct factory paint code ensures your touch-up job blends seamlessly with the rest of your truck.

Below is the complete guide to 2018 GMC Sierra 1500 paint codes, where to locate the manufacturer sticker, and tips on applying touch-up paint for a flawless finish.

Quick reference

Here are the factory colors offered for the 2018 GMC Sierra 1500. General Motors typically uses two formats for paint codes: a short RPO code (e.g., GAZ) and a longer WA code (e.g., WA8624). Both refer to the exact same paint formula.

Color Name	Paint Code (RPO / WA)	Type
Summit White	GAZ / WA8624	Solid
Onyx Black	GBA / WA8555	Solid
Quicksilver Metallic	GAN / WA636R	Metallic
Cardinal Red	G7C / WA130X	Solid
Dark Slate Metallic	GPA / WA457B	Metallic
Stone Blue Metallic	G1K / WA402Y	Metallic
White Frost Tricoat	G1W / WA140X	Pearl/Tri-coat
Red Quartz Tintcoat	GPJ / WA434B	Metallic/Tintcoat
Pepperdust Metallic	GMU / WA441B	Metallic
Deep Mahogany Metallic	G2X / WA439C	Metallic

Note: If you are uncertain about your specific color, always confirm your paint code via your VIN at a local GM dealer or through your chosen paint supplier.

Where to find your paint code

Locating the exact paint code on your 2018 GMC Sierra 1500 is quite straightforward. General Motors uses a "Service Parts Identification" (SPID) label, which lists all the factory options and codes built into your specific truck.

1. Glove Box: Open the passenger-side glove compartment. The sticker is usually affixed to the inside of the glove box door or along the inner side wall.
2. Driver’s Side Door Jamb: On many late-model GM trucks, there is also a secondary tire/certification label on the B-pillar (where the driver's door latches) that may include the paint code.

Look for a code starting with "U" (Upper) or "WA". It is usually located at the very bottom of the sticker and is preceded by "BC/CC" (Basecoat/Clearcoat). For example, if your truck is Summit White, the code will read U8624 or WA8624.

Best touch-up paint sources

When it comes to sourcing high-quality, color-matched paint, you have several reliable options:

• Your Local GM/GMC Dealer: OEM ACDelco touch-up paint pens and small bottles are perfect for minor chips and guarantee an exact factory match.
• AutomotiveTouchup: A highly recommended source for larger projects. They offer custom-mixed paint in pens, brush-in-bottles, aerosol cans, and ready-to-spray pints/quarts.
• Dupli-Color: Available at most auto parts stores. Look for their "Perfect Match" line. It is a highly accessible and affordable option, though color selection may be limited to the most popular shades like Summit White or Onyx Black.
• Tcoat Custom-Mix: Great for professional-grade touch-up kits that include everything you need to clean, prep, and paint small damage areas.

How to use touch-up paint

Achieving a smooth, invisible repair requires patience and proper technique. Follow these basic steps:

1. Clean: Wash the area thoroughly with soap and water. Follow up with a wax and grease remover or rubbing alcohol to remove any contaminants.
2. Primer (if needed): If the scratch goes all the way down to the bare metal or plastic, apply a very thin layer of automotive primer. Let it dry completely.
3. Basecoat: Apply the color paint in thin, light dabs or coats. Do not try to fill a deep chip in one go. Allow 15-20 minutes of drying time between each coat until the paint is level with the surrounding area.
4. Clearcoat: Once the basecoat is fully dry (usually wait at least 30-60 minutes), apply the clearcoat. The clearcoat protects the base and gives the repair that glossy factory shine. After a few days, you can lightly polish the area to blend the edges.

Color matching tips for pearls and tri-coats

Colors like White Frost Tricoat (G1W) or Red Quartz Tintcoat (GPJ) are notoriously difficult to touch up. These are "tri-coat" paints, meaning they require three separate layers at the factory: a solid base color, a translucent metallic/pearl mid-coat, and a protective clearcoat.

• Buy a Tri-Coat Kit: Make sure your touch-up supplier provides both the basecoat and the specific pearl mid-coat. A standard basecoat will not match.
• Test on a Card First: Practice on a piece of cardboard or metal first. The final color of a tri-coat changes depending on how many layers of the pearl mid-coat you apply.
• Less is More: Apply the mid-coat very sparingly. It is easy to make the patch look too dark or too sparkly if you overapply the pearl layer.

For large areas or complex tri-coat repairs that go beyond a simple rock chip, DIY touch-up paint might not yield perfect results. Find a trusted body shop on Repairius to restore your Sierra to showroom condition.