Colorful QR codes are great — until they stop scanning. The key is contrast.

Dark modules, light background

Most scanners expect the QR modules to be darker than the background. Keep that relationship.

Avoid “same brightness” colors

Two different colors can still have similar brightness. That’s when scans fail.

Print changes everything

Paper texture, ink, and lighting can reduce contrast. If it’s borderline on screen, it’s risky in print.