Add a thin, faint grey or blue line to the edges of the polygons to give them a "3D" or "technological" feel.

Since 1191x670 is a non-standard screen resolution, you might want to generate your own to ensure perfect sharpness:

Ensure the "polygons" aren't all one flat hex code. Use subtle gradients (e.g., #000000 to #1A1A1A) to simulate depth.

If you are looking for high-quality versions of this specific aesthetic, search for these keywords on stock or wallpaper sites:

Often yields these geometric, sharp-edged patterns. 2. Creating Your Own (Custom Fit)

A 1-3% film grain overlay can prevent "color banding" (the ugly stripes you sometimes see in dark gradients). 4. Implementation Tips