Everything the human eye sees is formed from the three primary colours of red, green and blue which when mixed with each other form all the shades and colour variations which we recognise.
The screens that we rely on such as televisions, computer monitors and smart phones also use this method to display colours. It is commonly known as the RGB format.
Each primary colour has 256 values (0 -255 with 0 representing none), the mathematical possibilities giving us a possible (256 x 256 x 256) 16,777,216 different colours
No-one can differentiate between millions of colours although, depending on the individual health of our eyesight, we can recognise different shades of many.
However, our screens often display those colours slightly differently according to their quality and when they were last calibrated. The software used by different users may also produce different results.
Once you send your artwork to a printer a different colour format is used. Printing machines typically utilise a format known as CMYK where C=Cyan, M=Magenta, Y=Yellow and K=Key (or what we normally think of as black.
These colours are not only different to the primary colours of RGB but are mixed in different units with different results meaning that an exact match to what you may see on your screen is different to the final print.
There is more to the subject than is explored here but suffice to say that your file must be converted to CMYK format before submitting it for production.
This is something included in our print service with a proof emailed to you before we proceed.