Mercedes-Benz Horizon Blue Metallic (391/5391) Touch Up Paint

The Look

Horizon Blue was the defining face of the B-Class during the mid-2000s, offering a look that was more sophisticated than a standard silver but more practical than a deep navy. Since your car has been on the road for over a decade, you've likely noticed how well this shade masks road grime and light dust. It is a professional, airy color that gives the car a sense of height and cleanliness. However, because it relies on a very specific balance of blue and grey tones, a poorly matched repair will stand out against the original panels.

Technical Details

This is a true metallic finish, meaning the paint is packed with tiny aluminum flakes that catch the light. While these flakes are great for hiding small surface imperfections, they are temperamental during application. If you apply the paint too heavily in one spot, those flakes will sink to the bottom of the wet layer, causing the repair to look much darker or "bruised" compared to the rest of the car. If you do not keep the container moving, you risk creating stripes where the flakes bunch up. Success with this color depends entirely on an even touch to keep those flakes sitting flat and uniform.

Best Practices

You will usually find your color ID on a sticker located on the driver's side door jamb or occasionally on the radiator support bar under the hood. Before you spray or dab Mercedes-Benz Horizon Blue Metallic (check for code 391/5391), you need to shake it for 60 seconds. This is non-negotiable for metallics because the heavy flakes settle at the bottom of the container almost immediately. Test the color on the included card first to ensure the flake density matches your car's current look. Work in a cool, covered area like a garage or the shade to manage the drying time, and always apply several thin layers rather than one thick coat to maintain the correct flow and color depth.