Lexmark C772 User Manual

Page of 112
Solving color quality problems
98
Troubleshooting
Solving color quality problems
This section helps answer some basic color-related questions and describes how some of the features provided in the 
Quality Menu can be used to solve typical color problems.
Note: See the quick reference page entitled “Print quality and troubleshooting guide” which provides 
solutions for common print quality problems, some of which may affect the color quality of the printed 
output.
Frequently asked questions (FAQ) about color printing
What is RGB color?
Red, green, and blue light can be added together in various amounts to produce a large range of colors observed in nature. 
For example, red and green light can be combined to create yellow light. Televisions and computer monitors create colors in 
this manner. RGB color is a method of describing colors by indicating the amount of red, green, and blue light needed to 
reproduce a particular color.
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 applications typically specify document color using RGB or CMYK color combinations. Additionally, they 
commonly let users modify the color of each object in a document. Since the procedures to modify colors vary depending 
on the application, see the software application Help section for instruction.
How does the printer know what color to print?
When a user prints a document, information describing the type and color of each object in the document is sent to the 
printer. The color information is passed through color conversion tables that translate the color into appropriate amounts of 
cyan, magenta, yellow, and black toner needed to produce the desired color. The object type information lets different color 
conversion tables be used for different types of objects. 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 the PostScript or PCL emulation driver for the best color? What driver 
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 
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 be generated on a computer screen that cannot be physically reproduced on a color laser printer. Color 
match can also be affected by monitor variations and lighting conditions. See the response to the question How can I 
match a particular color (such as a color in a corporate logo)? on page 99
 for recommendations on how the printer 
Color Samples pages may be useful in solving certain color-matching problems.