RGB and CMYK Color Modes
Ever see a picture on the internet or on your computer monitor that looks bright and vivid in color? Then you go to print it out and think, “It doesn’t look like this on my screen.”
There are several factors that can contribute to this. One of these factors is color mode.
When a user generates graphics on a computer for printing, or wishes to print images from a digital camera, it is a common mistake to assume that the colors seen on the screen will look the same in print. The issue lies in the fact that the computer screen and many photo editing programs show colors in Red-Green-Blue (RGB) mode, while images are printed on paper in Cyan-Magenta-Yellow-Black (CMYK) format.
In order to print properly, any image files that you supply for CMYK printing must be in CMYK mode. RGB files will look good on screen, and they will even look good when printed on many of the desktop color printers on the market today, however, they will not separate properly when the file is used to make printing plates. The resulting full printing job will not look the way you expect it to look. The RGB scheme has a greater range of colors than CMYK and can produce colors that are more vivid and vibrant. These colors are beyond the range of CMYK to reproduce and will come out darker and more dull in print than what is seen on the monitor or display. Sometimes the conversion from RGB to CMYK works without any problems arising, and a printout will look identical to what shows up on the computer. In other cases, there will be noticeable differences between the shades of color. The key to avoiding this potential problem is to convert all graphics to CMYK format during the layout design phase.
Even though it can be minimal, you can still see the difference in brightness on the photos below