The following guide explains the difference between the primary color gamuts: RGB and CMYK.
The RGB color model
The RGB color model is an additive color model that starts out from a black canvas – like a television, or a computer screen, and colors are added to create the final image. The colors Red Green and Blue are mixed and matched to produce a spectrum of colors.
The CMYK color model
The CMYK color model is a deductive color model that starts out from a white canvas, and colors Cyan, Magenta, Yellow and Key(black). The canvas (white) is essentially the sum of all the colors in the spectrum. You can produce a color by deducting colors from the spectrum.
Using the right color model
It is usually best if you use a CMYK color model on print files. The RGB color model has some colors that are not available under the CMYK spectrum – like most bright colors like fluorescent green or orange. Also, the usual printing medium is white paper, or canvas. Images that have been prepared using RGB needs to be converted to the CMYK model first before printing to achieve the best results.
Converting RGB images to the CMYK color model may be impossible if you do not have the right software handy. A very good example for helping you edit your images is Adobe Photoshop. Adobe Photoshop can change and adjust the color balance after conversion to match the intended color output.
When designing any file for print, it is important to design the file in CMYK color. Creating an image under the CMYK color profile prevents any problem that would arise when converting an image from the RGB color profile to CMYK. Not all word and image-processing software can create an image using the CMYK profile. Microsoft Word and Powerpoint are among the software that can only produce images or files using the RGB color profile. There are other alternatives to choose from that can produce images and files in the CMYK color profile, like Adobe Photoshop, InDesign, Illustrator and Microsoft Publisher.
Setting up for printing
When setting up your file for commercial printing, use printed CMYK color swatches to check the colors if you are unsure. Also, it would greatly help if you would proof the images using a color-calibrated monitor. Images’ colors may vary from monitor to monitor, and an uncalibrated monitor may cause errors that would only be revealed upon printing. If possible, you can print a sample using a commercial-proof printer with an output profile set to Fogra39. Use the Acrobat Pro preview tool to check colors when printing to an output set to Fogra39. Do not use a desktop printer for sampling because its profiles will generally try to emulate RGB colors as opposed to printing the true CMYK colors.
