A world of difference between QR codes intended for computer screens, video and TV and those used for printed matter.

Choosing the right QR code colour

And it even applies to black and white QR codes too. There are two basic colour models that are interesting for QR codes. The one for 2D codes displayed on computer screen, used in video or on television. This colour model is called 'RGB' (Red Green Blue). The second is used in the printing industry for printing coloured text, images, graphics and of course QR codes as well. This colour model is called CMYK (Cyan Magenta Yellow Black).

These two colour models are complete opposites of each other. Lets see how this works....

RGB 

Is used for radiant media like computer screens and television it is made up of three basic colours : red green and blue. If all colours are not used (switched off) you have a black screen. As you add more of each colour it becomes lighter. Adding 100% of each colour will then give as result a white screen. Thus the more colour, the lighter it shows.

CMYK 

Used for reflective media, like white paper. It is made up of four basic colours with one (Black) being an interesting one. Here no colours (or ink) means a white sheet of paper, and the more of a colour you add the darker it becomes. It is thus the exact opposite of radiant media. using Cyan + Magenta + Yellow should give us black, but instead it turns into a very dirty bark brown, and costs a lot of ink from each colour to achieve this. So black is added as fourth colour to ensure a solid black colour and minimize the amount of colour ink(s) needed to achieve this.

RGB Colour Model	CMYK Colour Model

From this we can see that printing QR codes created with a RGB colour model may look great on your screen, but your printer does not want them as even if your QR code is black and white, the black will translate to 100% cyan, 100% magenta and 100% yellow which is exactly what you printer does not want.

Sample PDF QR Code using each colour model, see which one your printer prefers. Click on the images below to download the PDF files.

RGB PDF QR Code	CMYK PDF QR Code

So next time you create a QR code, think first where it is going to be used, for display on a screen or for printing and choose the correct colour model to get the right results. If required for both media it is advisable to generate it twice using both colour models.