The metallic "look" isn't a color—it's **Specular Reflection**. If the laser pits the surface, the result is **Diffuse Scattering**, turning your vibrant marks into a matte, frosted gray.
Act I: The Bug
The "Sandpaper" Effect (Diffuse)
Laser Power80%
Roughness (Ra)
1.50 μm
Reflection
Diffuse
The Failure: High power vaporizes the metal surface irregularly, creating micro-pits. Because the surface peaks are larger than the wavelength of light, the reflection is scattered in all directions (Diffuse), appearing matte gray.
Act II: The Fix
The Mirror Finish (Specular)
Laser Power20%
Roughness (Ra)
0.05 μm
Reflection
Specular
The Success: By dropping power into the Annealing Window, we keep the surface smooth (Ra < λ). This preserves the mirror finish, allowing light to reflect cleanly (Specular), which is the prerequisite for vibrant colors.