QR code colors: how far you can go

A phone does not see colour when it reads a QR code. It converts the image to brightness and decides, module by module, whether each square is dark or light. Hue is irrelevant; the only thing that matters is how far apart the two brightness levels are, and which one is which.

That gives two rules. First, the modules must be the dark part and the background the light part, because that is the arrangement the standard describes and the one every reader expects. Second, the gap between them must survive real conditions: glare, shadow, a cheap printer, a camera that adjusts its exposure to the whole scene rather than the code.

Black on white maximises both, which is why it is the reference case. Every colour change spends some of that margin. Spending a little is fine; spending most of it produces a code that scans in the office and fails at the venue. How the reader samples modules is explained in how QR codes work.

A useful check: convert your design to greyscale. If the code still looks like a crisp black-and-white pattern, it will probably scan. If it looks like two shades of grey, it will not.

Inverted codes

Light modules on a dark background look striking and are popular on dark-themed packaging and slides. Many modern camera apps read them, but some readers do not, and you cannot choose which reader your audience uses. If the design demands a dark panel, put a white box inside it and place a normal dark-on-light code in that box, quiet zone included.

• Gradients across the modules. A gentle gradient between two dark colours can work. One that fades towards a light colour leaves part of the code with too little contrast, and a scanner needs all of it.
• Patterned or photographic backgrounds. Texture behind the code adds noise exactly where the scanner looks for clean light modules. Keep the code and its quiet zone on a flat, plain area.
• Transparent backgrounds. If you remove the white background from the file, the light modules become whatever is behind them. On white paper that is fine; dropped onto a dark photo or a coloured panel, the code may invert or vanish. Keep an opaque light background behind the code.
• Finishes. Metallic inks, foils, and gloss laminates reflect light into the camera and can wash out contrast that looked fine on screen.

The quiet zone must be the same light colour as the code’s background. A coloured border pressed up against the modules is read as part of the symbol and confuses the reader about where the code starts.

The generator here starts from black modules on a white background, the combination that scans on the widest range of phones. The custom QR code generator lets you pick a foreground and a background colour, and it enforces the rules above: the foreground must be the darker of the two, the contrast ratio must be at least 4.5:1, and inverted codes are refused. The PNG and SVG downloads both carry the colours you chose.

You can also download the SVG and recolour the modules in a design tool such as Illustrator, Affinity, Inkscape, or Figma — useful for an exact print colour. Because the code is made of plain vector shapes, changing the fill is a single step, but nothing then checks the contrast for you. Why SVG is the right file for this is covered in PNG vs SVG. Either way:

1. Change only the module colour first, keeping the white background and quiet zone.
2. Check the greyscale version: the modules should still look nearly black.
3. Print or display it at its final size, on its final material.
4. Scan it with at least three phones, including an older one, in dim and bright light.
5. If any of them hesitates, darken the colour or go back to black.

If a recoloured code stops scanning, the troubleshooting guide walks through the other usual suspects before you blame the colour.

Pick colours with the contrast checked for you:Make a custom QR code