The eagerly awaited proof book has arrived. With bated breath and a heady sense of exhilaration, your hands rip open the box. At that first glimpse of the cover, your excitement turns to dismay.

This isn’t the beautiful image you expected. Instead, the intensity of the black is muddy and dull. The bright neon green and brilliance of the blue has darkened. This is a frequent problem that arises when a color conversion occurs during the print process.


RGB (red, green and blue) and CMYK (cyan, magenta, yellow, and black) are the primary color systems.

RGB is the standard for the display of colors on electronic devices. CMYK is the color system for anything that is printed. As books are published in digital and print versions, both color schemes are used. This adds to the complexity of the publishing process.


Most graphic design programs use RGB as the default color system. While this works great for the eBook, it doesn’t for the print version.

Book covers are printed from a PDF. If the PDF was created from an image with the RGB color scheme, the colors will be converted to CMYK during the print process. The change may create an undesirable effect.

The adjacent images illustrate the difference between RGB and CMYK. The colors on the top row are RGB. The bottom row is the same color converted to CMYK.

Depending on the program used to create a book cover, images or text be inserted as CMYK. RGB images can also be converted to CMYK.

Microsoft Publisher is another design program with an option to select a CMYK color. The feature is a useful tool to assess the effect of a color shift or to experiment with assorted colors.

For a comparison on a color, open a blank document in Publisher. Insert a shape. Blue is the default color. Copy and paste to create a second shape.

To change the color to CMYK, select one of the inserted shapes. Click on “Drawing Tools,” then “Shape Fill.” Select “More Fill Colors” and “Custom.” The “Color Model” is set to the default color system: RGB. Click on the arrow and select CMYK to convert the color. The CMYK color shift in the selected shape will be apparent when compared to the shape set to RGB.

Understanding the application and difference between RGB and CMYK will improve the final result: Your Book Cover.

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