Colourful QR Code solutions with QR4.
Using colour to create more attractive QR codes could be the trigger for it to be scanned or not by making the QR code stand out from the crowd.
| Normal QR code
|| QR code with colour
|| Contrasted QR code
|| Colourized QR code
Other advantages are making the QR codes match company colour schemes to make it blend into the documents or media it is printed on for a more professional 'look and feel'. There are a few important things to keep in mind when using colours with QR codes because not all colour combinations will work, and even if some do, they may not work on older mobile devices or outdated QR Code Apps.
There is a very good reason QR codes are black and white, the reason is contrast. The bigger the difference in colour between the background and the data elements, the better is it to read. When it comes to the ultimate contrast, you cannot get better than black and white. Any other colour combination will have an effect on the contrast and thus the ability for scanner applications to read it successfully.
The golden rule when working with colours is to keep the background and foreground colours contrasting each other as much as possible. To do this we need to determine which colours 'oppose' each other and for this we can use a colour wheel.
Below is the QR code colour wheel, where 'S' is the start and 'E' is the end colour. The idea is try and choose an ending colour that is 180 degrees from your starting colour, as this should give the best results. As you choose ending colours closer to your starting colour, the contrast becomes smaller and this will effect the ability for applications to read your QR code successfully.
Wait, we are not finished yet!
This is about QR code scanner applications and the developers who build them as well as mobile devices with camera's.
Unfortunately not all mobile phone camera's are of the same quality and even more so for QR code scanner application developers. To date there are hundreds of different QR code scanners for mobile phones that can be downloaded for 'free' from a variety of on-line application stores. Our findings are that most of them lack severely in the ability to decode QR codes correctly. So do not 'just download the first best app you find!'
Having said this, I am assuming that the developers do honour the ISO specification for QR codes, and here it is clearly stated it should (must) be black and white. So who is at fault if your colour QR code cannot be read, you are !
The good old times of QR codes
Older mobile devices like my 'mini-fridge' Nokia N95 that came with pre-installed qr code readers use a trick that is still used by developers today, although it should not be required anymore....Let me explain, it's called being colourblind and this has a big impact on the ability to detect and decode QR code images.
In the past storage and processing on mobile devices was a lot more limited than the smart devices of today and some cleaver tricks were developed to make this work for QR code scanners. They used image conversion from colour to black and white before processing the image. Why? Because black and white images are digitally smaller because each pixel does not have any colour information. Because the image was smaller it could be processed faster. Today this method is still in use with some readers and this has a whole new influence on our colour wheel.
Suddenly we can see why some QR code readers may not be able to read the QR codes if we take into consideration the requirement for 'maximum contrast' we can clearly see that the selections of colours we can use in the 'colour world' could bee seen as the same 'shade of gray' in the 'black and white world. If we want to make colour QR codes for a 'black and white world' our colour contrast selection becomes even more limited.
Acoording to the specifications
QR codes should be black and white only, so taking our colour wheel and converting it to black and white based on a 50% conversion threshhold we see how a single bit image processor would see the colours.
The good news about colour QR codes
As new generations of smart phones are replacing the older mobile devices in the market, the problem of gray-scale QR code interpretors should become less, but until the day that all smart-phones have perfect camera's and developers write ultimate intelligent QR decoding software and applications, this developer will still always test the QR codes with old legacy decoder systems. As final itam and maybe the most important tip is to always test the QR codes you create as best you can with different QR reader applications and with different types of smart-phones. Just because it works on your device is no guarantee it will work for everyone.
Colour QR Code generator list
Most of the QR code generators here at QR4 support the use of colour and other advanced features such as transparency and opacity. You are welcome to test generating QR codes in colour for yourself. Remember that the secret to success is to test your QR codes thoroughly. Should you have any comments, questions or need advice about using colour with QR codes, please contact us.