I have sent a file to a client which was saved in CMYK colors. They opened the file and the colors are nothing like the original design. Any ideas what is happening here? Any help is much appreciated.
Bottom line: you can't guarantee a file's colors to look identical on any two screens.
First, CMYK is nothing but an approximation, as long as it's on your screen. RGB and CMYK are so fundamentally different color spaces that it's impossible to display the one in the other, even if you calibrate.
That said, calibration (or lack thereof) are wildly different between different machines. In addition, people have different preferences for their screen settings like brightness, contrast and saturation.
Lastly, if you are talking about a
*.pdfs. If your client uses a different viewer than you are, there's a 99 in 100 chance that color display is off.
Incorporating Gramps's comment, it might be a good idea to inform the client of the fact that only actual printing will give a proper idea of the colours.
I have been having this problem too and I cant figure out why. But what I did to solve this problem was save the illustrator file as a PDF. Then I open the PDF in Photoshop and save it as a JPEG. When sending that JPEG file the colors were sent correctly. Hope this helps but I wish I knew how without all those extra steps.
Color is not a simple thing, each and every monitor and sensing environment is different. Hell even just changing the lights change color. Even paper makers realized this years ago. White in northern Europe is light blue in the tropics, whereas white of a tropical ay is yellow in the north. While its partially culturally preferred you can actually observe this yourself if you fly to check it out.
Each and every monitor on the planet is different! CMYK and RGB does not matter. Each monitor shifts over time uniquely. Also the ambient lighting changes during the day. So even if your monitors are calibrated there's error, and the longer its been since they have been calibrated the more error. Even calibration tools will cause some error.
This is why you need a profile. However most users dont have calibrated monitors, thus no profile helps. But even a profile does not really help in cases where the color is outside the displayable range. You can manage this but the entire system must be closed loop and each user well trained... Which is a bit hard to achieve with the average client.
But that okay, your clients will not likely notice any difference.