One of the most difficult colors to reproduce is a bright Azure blue (a bright mix of blue and cyan). I have tried many methods and color corrections and still have been unsuccessful in close color reproduction. As you can see in the side by side comparison screen shot, the colors look great on the screen. But when I print them, the inks and media drop the intensity of the blues and cyans becoming faded, muddied and flat.
To visualize the effect of print I use a method called “soft proofing”. I apply a soft (or visual proof) by going to the “view” menu in Photoshop and choosing “proof set-up”. From that drop down menu I choose “custom” and then select the paper and printer profiles I have for my printer. (In this case it is Epson 9800 Dual Black inks Breathing Color Chrome White Canvas) The bottom screen shot shows the results on both of my test prints. Before I even print them, I know the image on the Left will not even come close to the original despite it being closer in color on the computer screen.
Because I have had this issue before with this color, I have managed to find a way to reproduce it coming fairly close. I usually work in RGB color mode and send all files to my printer in RGB. (Image>Mode>RGB color). As this is the color mode of the computer and the color mode that the printer reads I always work in this mode. However, achieving this brilliant azure blue in RGB is not possible. So I convert the color mode to Lab color and I am able to create the correct color on screen and from the printer. Color correction can usually be done by the numbers but when it comes to colors that are out of gamut it sometimes takes intuitive reasoning and experimentation. Don’t be afraid to experiment in Photoshop. It is sometimes the only way to get the effect you want