Many people are surprised when they receive their printed piece to find that the color blue they wanted has now become purple. What they are not aware of is that blue is close to purple in the CMYK spectrum. Because monitors as well as some programs being used are in RGB, they do not see the changes that are made when printing converts their files from RGB to CYMK.


RGB refers to the primary colors of light, Red, Green and Blue, that are used in monitors, television screens, digital cameras and scanners. CMYK refers to the primary colors of pigment: Cyan, Magenta, Yellow, and Black. These are the inks used on the press in “4-color process printing”, commonly referred to as “full color printing”. The combination of RGB light creates white, while the combination of CMYK inks creates black. Therefore, it is physically impossible for the printing press to exactly reproduce colors as we see them on our monitors.

Many programs such as photoshop and illustrator have the capability to convert the layout/images from the RGB color space to the CMYK color space. We request that you convert your colors from RGB to CMYK if your tools allow you to. By doing it yourself, you have maximum control over the results. Especially with blues, You willy notice a shift in color when converting from RGB to CMYK. If you do not like the appearance in CMYK, we recommend that you make adjustments while working in CMYK.


blue rgb vs Cymk blue


When using a blue in your design, always make sure to leave at least a 30% difference in your Cyan and Magenta values.
Here is an example of how your screen blue can print completely different from your print blue. (100% C 100% M 0% Y 0% K) See the result…

Remember, use a low amount of magenta whenever using high amounts of cyan to avoid purple. This problem does not always show up on proofs due to RGB monitors.


A pleasing shade of blue may be 100-70-0-15. The more black added the darker the color. For those of you wanted to use a reflex blue, it is impossible for the printing to achieve this. The process can not duplicate this color.


The best suggestion is to work in CYMK. That is the only way you can be sure what color blue you will achieve. Keep in mind the rule of 30% and use black to darken or lighten your color. When designing for printing, you must use the CYMK color mode. That is the only way you can be sure that what you have designed will print correctly. Having your blue not turn purple is possible, Printing a pleasing blue can only be achieved by following the CYMK rule.


What is CYMK? Commercial color printing uses 4 colors, Cyan, Magenta, Yellow and Black, also referred to as process colors. It is theoretically possible to make about 10,000,000 colors using screens with tiny dots of each of the 4 colors from 0 – 100%.  The more dots the better detail. For high quality printing the standard number of dots per inch (DPI) is 300, some offer 500 DPI. Process inks are opaque and transparent so the can produce the desired color using different percentages of each of the four colors.

Pantone® is an international organization that established a matching color system, (PMS) using to describe each color. Pantone® colors have exact standards and formulas so the can be duplicated worldwide. This system is use by printers and designers in every field including paint, interior design, fabrics and where color is critical. Pantone® colors are made by ink manufactures for the print industry.  The ink is best described as “spot color”. Spot colors are colors that don’t require screens because these are applied as a solid color.  Spot colors cannot be created in CYMK or on your RGB computer screen. The only way to match them is using a Pantone® swatch book.

Color gamut is the range of colors that can be made in CYMK and RGB and other color matching systems. CYMK has the smallest color gamut; RGB has a larger gamut and other color less popular color systems where combinations of colors are used can only simulate PMS.

For very custom jobs only a few online printing services can combine process color and with PMS colors. This requires a printing press that can print 5, 6, 8 or more colors at the same time. These kinds of jobs are not inexpensive, but can achieve spectacular effects with brighter, richer colors and metallic or florescent inks. These additional PMS colors make a spectacular presentation the will not go unnoticed.