Why colors sometimes don’t match

No device in a publishing system is capable of reproducing the full range of colors viewable to the human eye. Each device operates within a specific color space that can produce a certain range, or gamut, of colors.

A color model determines the relationship between values, and the color space defines the absolute meaning of those values as colors. Some color models (such as CIE L*a*b) have a fixed color space because they relate directly to the way humans perceive color. These models are described as being device-independent. Other color models (RGB, HSL, HSB, CMYK, and so forth) can have many different color spaces. Because these models vary with each associated color space or device, they are described as being device-dependent.

Because of these varying color spaces, colors can shift in appearance as you transfer documents between different devices. Color variations can result from differences in image sources; the way software applications define color; print media (newsprint paper reproduces a smaller gamut than magazine-quality paper); and other natural variations, such as manufacturing differences in monitors or monitor age

Working Space options

To display working space options in Photoshop, Illustrator and InDesign, choose Edit > Color Settings. In Acrobat, select the Color Management category of the Preferences dialog box. To view a description of any profile, select the profile and then position the pointer over the profile name. The description appears at the bottom of the dialog box. RGB Determines the RGB color space of the application. In general, it’s best to choose Adobe RGB or sRGB, rather than the profile for a specific device (such as a monitor profile). sRGB is recommended when you prepare images for the web, because it defines the color space of the standard monitor used to view images on the web. sRGB is also a good choice when you work with images from consumer-level digital cameras, because most of these cameras use sRGB as their default color space.

Adobe RGB is recommended when you prepare documents for print, because Adobe RGB’s gamut includes some printable colors (cyans and blues in particular) that can't be defined using sRGB. Adobe RGB is also a good choice when working with images from professional-level digital cameras, because most of these cameras use Adobe RGB as their default color space.

CMYK Determines the CMYK color space of the application. All CMYK working spaces are device-dependent, meaning that they are based on actual ink and paper combinations. The CMYK working spaces Adobe supplies are based on standard commercial print conditions.

1. Gray (Photoshop) or Grayscale (Acrobat) Determines the grayscale color space of the application.

2. Spot (Photoshop) Specifies the dot gain to use when displaying spot color channels and duotones.

Note: In Acrobat, you can use the color space in an embedded output intent instead of a document color space for viewing and printing. Select Output Intent Overrides Working Spaces.

Adobe applications ship with a standard set of working space profiles that have been recommended and tested by Adobe Systems for most color management workflows. By default, only these profiles appear in the working space menus. To display additional color profiles that you have installed on your system, select Advanced Mode (Illustrator and InDesign) or More Options (Photoshop). A color profile must be bi‑directional, that is, contain specifications for translating both into and out of color spaces, in order to appear in the working space menus.

Note: In Photoshop, you can create custom working space profiles. However, Adobe recommends that you use a standard working space profile rather than create a custom profile.

About missing and mismatched color profiles

For a newly created document, the color workflow usually operates seamlessly: unless specified otherwise, the document uses the working space profile associated with its color mode for creating and editing colors. However, some existing documents may not use the working space profile that you have specified, and some existing documents may not be color-managed. It is common to encounter the following exceptions to your color-managed workflow:

You might open a document or import color data (for example, by copying and pasting or dragging and dropping) from a document that is not tagged with a profile. This is often the case when you open a document created in an application that either does not support color management or has color management turned off. You might open a document or import color data from a document that is tagged with a profile different from the current working space. This may be the case when you open a document that was created using different color management settings, or scanned and tagged with a scanner profile.

In either case, the application uses a color management policy to decide how to handle the color data in the document. If the profile is missing or does not match the working space, the application may display a warning message, depending on options you set in the Color Settings dialog box. Profile warnings are turned off by default, but you can turn them on to ensure the appropriate color management of documents on a case-by-case basis. The warning messages vary between applications, but in general you have the following options:

(Recommended) Leave the document or imported color data as it is. For example, you can choose to use the embedded profile (if one exists), leave the document without a color profile (if one doesn’t exist), or preserve the numbers in pasted color data.

Adjust the document or imported color data. For example, when opening a document with a missing color profile, you can choose to assign the current working space profile or a different profile. When opening a document with a mismatched color profile, you can choose to discard the profile or convert the colors to the current working space. When importing color data, you can choose to convert the colors to the current working space in order to preserve their appearance.

About color profiles

Precise, consistent color management requires accurate ICC-compliant profiles of all of your color devices. For example, without an accurate scanner profile, a perfectly scanned image may appear incorrect in another program, simply due to any difference between the scanner and the program displaying the image. This misleading representation may cause you to make unnecessary, time-wasting, and potentially damaging “corrections” to an already satisfactory image. With an accurate profile, a program importing the image can correct for any device differences and display a scan’s actual colors.

A color management system uses the following kinds of profiles :

Monitor profiles Describe how the monitor is currently reproducing color. This is the first profile you should create because viewing color accurately on your monitor allows for critical color decisions in the design process. If what you see on your monitor is not representative of the actual colors in your document, you will not be able to maintain color consistency.

Input device profiles Describe what colors an input device is capable of capturing or scanning. If your digital camera offers a choice of profiles, Adobe recommends that you select Adobe RGB. Otherwise, use sRGB (which is the default for most cameras). Advanced users may also consider using different profiles for different light sources. For scanner profiles, some photographers create separate profiles for each type or brand of film scanned on a scanner.

Output device profiles Describe the color space of output devices like desktop printers or a printing press. The color management system uses output device profiles to properly map the colors in a document to the colors within the gamut of an output device’s color space. The output profile should also take into consideration specific printing conditions, such as the type of paper and ink. For example, glossy paper is capable of displaying a different range of colors than matte paper.

Most printer drivers come with built‑in color profiles. It’s a good idea to try these profiles before you invest in custom profiles.

Document profiles Define the specific RGB or CMYK color space of a document. By assigning, or tagging, a document with a profile, the application provides a definition of actual color appearances in the document. For example, R=127, G=12, B=107 is just a set of numbers that different devices will display differently. But when tagged with the AdobeRGB color space, these numbers specify an actual color or wavelength of light; in this case, a specific color of purple.

When color management is on, Adobe applications automatically assign new documents a profile based on Working Space options in the Color Settings dialog box. Documents without assigned profiles are known as untagged and contain only raw color numbers. When working with untagged documents, Adobe applications use the current working space profile to display and edit colors.

Distortion Tools

Some of the tools in the Liquify dialog box destructive brush area when you press the mouse button or drag. That focused on the distortion is the center of the brush area, and the effect intensifies as you press the mouse button or repeatedly drag over an area.

Forward Warp tool: a tool component pushes pixels forward as you drag. Shift-click with the warp tool, Push Left tool, mirror or tool to create interesting effects in a straight line from the previous point you clicked. Twirl Clockwise Tool: rotates pixels clockwise as you press the mouse button or drag.To rotate counterclockwise pixels, press Alt (Windows) or Option (Mac OS) as you press the mouse button or drag. Pucker Tool: Moves pixels toward the center of the brush area as you press the mouse button or drag. Bloat Tool: Moves pixels from the center of the brush area as you press the mouse button or drag. Push Left Tool: Moves pixels to the left when you pull the tool straight up (pixel moves to the right if you drag down). You can also drag an object around the clock to increase the size, or drag counterclockwise to reduce its size. To encourage the pixels when you drag the top right of the straight (or to move the pixels when you drag the bottom left), press Alt (Windows) or Option (Mac OS) as you drag. Mirror Tool Copies pixels to the brush area. Pull the mirror area perpendicular to the direction of a stroke (to the left of the stroke). Alt-drag (Windows) or Option-drag (Mac OS) to the mirror area in the opposite direction of the stroke (eg, the area above the downward stroke). Typically, Alt-drag or Option-drag to give better results when you have frozen the area you want to think. Overlap strokes used to create an effect similar to a reflection in the water. Turbulance Tools: smoothly scrambles pixels. This is useful for creating fire, clouds, waves, and the same effect. Liquify: tool of choice Tool of choice in the dialog box, specify the following options: Brush Size: Sets the width of your brush will be used to damage the image. Brush Pressure: Sets the speed of the distortions created when you drag a tool in the preview image. Using a low brush pressure makes changes occur more slowly, so they are easier to stop exactly at the right time. Brush Rate: Sets the speed of distortion that will be applied when you keep a tool (such as tool rotation) stationary in the preview image. Setting a higher level, the greater the distortion applied speed. Brush Density: Controls how the brush bristles at the edge. Strong effect on the middle and lightly brush on the edge. Turbulent Jitter: jitney strict control how the turbulence tool scrambles pixels. Reconstruct Mode: Used to return the tool, the mode you choose will determine how the tool reconstructs the image preview area. Select Stylus Pressure: Using the stylus pressure reading from the tablets. (This option is available only when you work with a stylus tablet.) When selected, the brush pressure to the tool stylus is pressure multiplied by the Brush Pressure value.