Lexmark X790 Series User Manual page 302

What is CMYK color?
Cyan, magenta, yellow, and black inks or toners can be printed in various amounts to produce a large range of
colors observed in nature. For example, cyan and yellow can be combined to create green. Printing presses, inkjet
printers, and color laser printers create colors in this manner. CMYK color is a method of describing colors by
indicating the amount of cyan, magenta, yellow, and black needed to reproduce a particular color.
How is color specified in a document to be printed?
Software programs typically specify document color using RGB or CMYK color combinations. Additionally, they
allow users to modify the color of each object in a document. For more information, see the software program
Help topics.
How does the printer know what color to print?
When a user prints a document, information describing the type and color of each object is sent to the printer.
The color information is passed through color conversion tables that translate the color into the appropriate
amounts of cyan, magenta, yellow, and black toner needed to produce the desired color. The object information
determines the application of color conversion tables. For example, it is possible to apply one type of color
conversion table to text while applying a different color conversion table to photographic images.
Should I use PostScript or PCL emulation printer software? What settings should I use for the best color?
The PostScript driver is strongly recommended for best color quality. The default settings in the PostScript driver
provide the preferred color quality for the majority of printouts.
Why doesn't the printed color match the color I see on the computer screen?
The color conversion tables used in Auto Color Correction mode generally approximate the colors of a standard
computer monitor. However, because of technology differences that exist between printers and monitors, there
are many colors that can also be affected by monitor variations and lighting conditions. For recommendations on
how the printer color sample pages may be useful in solving certain color-matching problems, see the question,
"How can I match a particular color (such as a corporate logo)?"
The printed page appears tinted. Can I adjust the color?
Sometimes a printed page may appear tinted (for example, everything printed seems to be too red). This can be
caused by environmental conditions, paper type, lighting conditions, or user preference. In these instances, adjust
the Color Balance setting to create a more preferable color. Color Balance provides the user with the ability to
make subtle adjustments to the amount of toner being used in each color plane. Selecting positive or negative
values for cyan, magenta, yellow, and black (from the Color Balance menu) will slightly increase or decrease the
amount of toner used for the chosen color. For example, if a printed page has a red tint, then decreasing both
magenta and yellow could potentially improve the color balance.
My color transparencies seem dark when they are projected. Is there anything I can do to improve the color?
This problem most commonly occurs when projecting transparencies with reflective overhead projectors. To
obtain the highest projected color quality, transmissive overhead projectors are recommended. If a reflective
projector must be used, then adjusting the Toner Darkness setting to 1, 2, or 3 will lighten the transparency. Make
sure to print on the recommended type of color transparencies.
What is manual color correction?
When manual color correction is enabled, the printer employs user-selected color conversion tables to process
objects. However, Color Correction must be set to Manual, or no user-defined color conversion will be
implemented. Manual color correction settings are specific to the type of object being printed (text, graphics, or
images), and how the color of the object is specified in the software program (RGB or CMYK combinations).
Troubleshooting
302