QR Code Color Selection and Contrast Rules

QR Code Color Selection

Color selection is critical for QR code readability.

Contrast Rule

There must be sufficient contrast between QR code and background:

Minimum contrast ratio: 3:1

Recommended ratio: 4.5:1 or higher

Ideal ratio: 7:1 (black-white)

Safe Color Combinations

Dark Background:

White QR on black background ❌ (reverse contrast)

Black QR on white background ✅

Colored QR Codes:

Dark blue QR + white background ✅

Light yellow QR + white background ❌

Purple QR + light pink background ❌

Gradient Usage

When using gradients:

There must be contrast between two colors

Even the lightest color should be dark enough from background

Gradient direction doesn't matter

Adding Logo

When adding logo:

Use high error correction (H level)

Logo size maximum 30%

You can hide dots under logo

Logo itself should be high contrast

Testing

Must test:

In different lighting conditions

With different phones

From different distances

Printed version

Common Mistakes

❌ Very light colors (pastel tones)
❌ Similar tones (gray QR + light gray background)
❌ Neon colors (may cause reading issues)
❌ Transparent or semi-transparent QR

Conclusion

For best results, use classic black-white combination. If you want colored QR, check contrast ratio.

QR Code Color Selection and Contrast Rules