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Specifying a color using the color field and color slider
With the HSB, RGB, and Lab color modes, you can use the color field and the color slider in
the Color Picker dialog box to select a color. The color slider displays the range of color
levels available for the selected color component (for example, R, G, or B). The color field
displays the range for the remaining two components—one on the horizontal axis, one on
the vertical.
For example, if the current color is black and you click the red component (R) using the
RGB color model, the color slider displays the range of color for red (0 is at the bottom of
the slider and 255 is at the top). The color field displays the values for blue along its
horizontal axis, for green along its vertical axis.
To specify a color using the color field and color slider:
1 Click a component next to the HSB, RGB, or Lab values.
2 Select a color:
•
Drag the white triangles along the slider.
•
Click inside the color slider.
•
Click inside the color field.
When you click in the color field, a circular marker indicates the color’s position in the field.
As you adjust the color using the color field and color slider, the numerical values change
to reflect the new color. The color rectangle to the right of the color slider displays the new
color in the top section of the rectangle. The original color appears at the bottom of the
rectangle.
Specifying a color using numeric values
In the Adobe Color Picker, you can select a color in any of the four color models by speci-
fying numeric values for each color component.
To specify a color using numeric values:
Do one of the following:
•
(Photoshop) In CMYK color mode (the mode PostScript printers use), specify each
component value as a percentage of cyan, magenta, yellow, and black.
•
In RGB color mode (the mode your monitor uses), specify component values from 0 to
255 (0 is black, and 255 is the pure color).
•
In HSB color mode, specify saturation and brightness as percentages; specify hue as an
angle from 0° to 360° that corresponds to a location on the color wheel. For more infor-
mation on the color wheel, see “
A
b
out c
olor mo
des and mo
dels (P
hot
oshop)
”
on
page
86
.
•
(Photoshop) In Lab mode, enter a lightness value (L) from 0 to 100 and a axis (green to
magenta) and b axis (blue to yellow) values from –120 to +120.
Using Web-safe colors
The Web-safe colors are the 216 colors used by browsers regardless of the platform. The
browser will change all colors in the image to these colors when displaying the color on an
8-bit screen. The 216 colors are a subset of the Mac OS 8-bit color palettes. By working only
with these colors, you can be sure that art you prepare for the Web will not dither on a
system set to display in 256 colors.
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To identify Web-safe colors in the Adobe Color Picker:
•
Click the Only Web Colors option in the lower left corner of the color picker, and then
choose any color in the color picker. Any color you pick with this option selected is
Web-safe.
•
Choose a color in the color picker. If you choose a non-Web color, an alert cube
appears next to the color rectangle in the color picker. Click the alert cube to select the
closest Web color. (If no alert cube appears, the color you chose is Web-safe.)
To select a Web-safe color using the Color palette:
1 Click the Color palette tab, or choose Window > Color to view the Color palette.
2 Choose an option for selecting a Web-safe color:
•
Choose Make Ramp Web Safe from the Color palette menu. With this option selected,
any color you choose in the Color palette is Web-safe.
•
Choose Web Color Sliders from the Color palette menu (Photoshop), or choose any
Slider option from the Color palette menu (ImageReady). By default, Web Color Sliders
snap to Web-safe colors (indicated by tick marks) when you drag them. (To override
Web-safe color selection, Alt-drag (Windows) or Option-drag (Mac OS) the sliders.) If
you choose a non-Web color, an alert cube appears above the color ramp on the left
side of the Color palette. Click the alert cube to select the closest Web color. In
ImageReady, drag around the alert icon to select other close Web colors. (If no alert
cube appears, the color you chose is Web-safe.)
Note: In Photoshop, you must choose Web Color Sliders from the Color palette menu to
view the Web-safe alert cube. In ImageReady, you can view the alert cube with any color
slider option.
Recognizing nonprintable colors (Photoshop)
Some colors in the RGB, HSB, and Lab color models, such as neon colors, cannot be printed
because they have no equivalents in the CMYK model. When you select a nonprintable
color, an alert triangle appears in the Color Picker dialog box and in the Color palette.
The closest CMYK equivalent is displayed below the triangle. (See “
Iden
tifying out-of-
gamut c
olors (P
hot
oshop)
”
on page
136
.)
Note: The alert triangle is not available if you’ve chosen to use Web-safe sliders.
Printable colors are determined by your current CMYK working space as defined in the
Color Settings dialog box.
To select the closest CMYK equivalent for a nonprintable color:
Click the alert triangle that appears in the Color Picker dialog box or the Color palette.
Choosing custom colors (Photoshop)
The Adobe Color Picker lets you choose custom colors from the PANTONE
®
MATCHING
SYSTEM
®
, the TRUMATCH
®
SWATCHING SYSTEM
™
, the FOCOLTONE
®
COLOUR SYSTEM, the
TOYO Color Finder
™
1050 system, the ANPA-COLOR
™
system, HKS
®
color system, and the DIC
Color Guide.
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To ensure that the final printed output is the color you want, consult your printer or
service bureau and choose your custom color based on a printed color swatch. Manufac-
turers recommend that you get a new swatch book each year to compensate for fading
inks and other damage.
Important: Photoshop prints custom colors to CMYK (process color) plates in every
image mode except Duotone. To print true spot color plates, create spot color channels.
(See “
A
dding sp
ot c
olors (P
hot
oshop)
”
on page
272
.)
To choose a custom color:
1 Open the Adobe Color Picker, and click Custom.
The Custom Colors dialog box displays the color closest to the color currently selected in
the Color Picker.
2 For Book, choose a color system. (See “
C
ho
osing a cust
om c
olor sy
st
em (P
hot
oshop)
”
on page
264
.)
3 Locate the color you want by entering the ink number or by dragging the triangles
along the scroll bar.
4 Click the desired color patch in the list.
Choosing a custom color system (Photoshop)
The Adobe Color Picker supports various color systems:
PANTONE Used for printing solid-color and CMYK inks. The PANTONE MATCHING SYSTEM
includes 1,114 solid colors. To select a color, use a PANTONE Color guide, printed on
coated, uncoated, and matte stocks.
To simulate a PANTONE solid color in CMYK, use the PANTONE Solid to Process Guide,
which displays a visual comparison of 1,089 solid PANTONE colors beside the closest
process color match.
PANTONE process guides let you choose from over 3,000 CMYK combinations, printed
coated and uncoated stocks.
TRUMATCH Provides predictable CMYK color matching with more than 2000 achievable,
computer-generated colors. TRUMATCH colors cover the visible spectrum of the CMYK
gamut in even steps. The TRUMATCHCOLORFINDER displays up to 40 tints and shades of
each hue, each originally created in four-color process and each reproducible in four
colors on electronic imagesetters. In addition, four-color grays using different hues are
included.
FOCOLTONE Consists of 763 CMYK colors. FOCOLTONE colors help avoid prepress
trapping and registration problems by showing the overprints that make up the colors.
A swatch book with specifications for process and spot colors, overprint charts, and a chip
book for marking up layouts are available from FOCOLTONE.
TOYO Color Finder 1050 Consists of more than 1000 colors based on the most common
printing inks used in Japan. The TOYO Color Finder 1050 Book contains printed samples of
Toyo colors and is available from printers and graphic arts supply stores.
ANPA-COLOR Commonly used for newspaper applications. The ANPA-COLOR ROP
Newspaper Color Ink Book contains samples of the ANPA colors.
DIC Color Guide Commonly used for printing projects in Japan.
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HKS Used for printing projects in Europe. Each color has a specified CMYK equivalent.
You can select from HKS E (for continuous stationary), HKS K (for gloss art paper), HKS N
(for natural paper), and HKS Z (for newsprint). Color samplers for each scale are available.
Using other color pickers
In addition to the default Adobe Color Picker, you can use the built-in color pickers on your
system or a plug-in color picker to select colors. Any plug-in color pickers you install
appear under Color Picker in the General section of the Preferences dialog box. For infor-
mation on installing and using a plug-in color picker, see the documentation that came
with the plug-in.
To use the Windows Color Picker (Windows):
1 Choose Edit > Preferences > General.
2 Choose Windows from the Color Picker menu, and click OK.
For more information, see your Windows documentation.
To use the Apple Color Picker (Mac OS):
1 Do one of the following:
•
In Mac OS 9.x, choose Edit > Preferences > General.
•
(Photoshop) In Mac OS X, choose Photoshop > Preferences > General.
•
(ImageReady) In Mac OS X, choose ImageReady > Preferences > General.
2 For Color Picker, choose Apple, and click OK.
The exact appearance of the Apple Color Picker varies between different system software
versions. For more information, see your Mac OS documentation.
To return to the Adobe Color Picker after using another color picker:
1 Do one of the following:
•
In Windows and Mac OS 9.x, choose Edit > Preferences > General.
•
(Photoshop) In Mac OS X, choose Photoshop > Preferences > General.
•
(ImageReady) In Mac OS X, choose ImageReady > Preferences > General.
2 Choose Adobe from the Color Picker menu, and click OK.
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Using Channels and Masks
About channels
Channels are grayscale images that store different types of information:
•
Color information channels are created automatically when you open a new image.
The image’s color mode determines the number of color channels created. For
example, an RGB image has four default channels: one for each of the red, green, and
blue colors plus a composite channel used for editing the image.
•
You can create alpha channels to store selections as 8-bit grayscale images. You
use alpha channels to create and store masks, which let you manipulate, isolate,
and protect specific parts of an image. In addition to supporting alpha channels
from Photoshop, you can save, load, and delete selections as alpha channels in
ImageReady 7.0.
•
You can create spot color channels to specify additional plates for printing with spot
color inks.
An image can have up to 24 channels. The file size required for a channel depends on the
pixel information in the channel. Certain file formats, including TIFF and Photoshop
formats, compress channel information and can save space. The uncompressed size of a
file, including alpha channels and layers, appears as the rightmost value in the status bar
at the bottom of the window when Document Sizes is chosen from the pop-up menu.
Note: As long as you save a file in a format supporting the image’s color mode, the color
channels are preserved. Alpha channels are preserved only when you save a file in Adobe
Photoshop, PDF, PICT, Pixar, TIFF, or Raw formats. DCS 2.0 format only preserves spot
channels. Saving in other formats may cause channel information to be discarded.
(See “
A
b
out fi
le f
ormats
”
on page
453
.)
Using the Channels palette (Photoshop)
The Channels palette lets you create and manage channels and monitor the effects of
editing. The palette lists all channels in the image—composite channel first (for RGB,
CMYK, and Lab images), then individual color channels, spot color channels, and finally
alpha channels. A thumbnail of the channel’s contents appears to the left of the channel
name; the thumbnail automatically updates as you edit the channel.
Viewing channels
You can use the palette to view any combination of individual channels. For example,
you can view an alpha channel and the composite channel together to see how changes
made in the alpha channel relate to the entire image. By default, individual channels are
displayed in grayscale.
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To display the Channels palette:
1 Choose Windows > Channels, or click the Channels palette tab.
2 Use the scroll bars or resize the palette to see additional channels.
When a channel is visible in the image, an eye icon appears to its left in the palette.
To show or hide a channel:
Click in the eye column next to the channel to show or hide that channel. (Click the
composite channel to view all default color channels. The composite channel is displayed
whenever all the color channels are visible.)
To show or hide multiple channels, drag through the eye column in the Channels
palette.
These guidelines apply to channels you display:
•
In RGB, CMYK, or Lab images, you can view the individual channels in color. (In Lab
images, only the a and b channels appear in color.)
•
If more than one channel is active, the channels always appear in color.
•
In alpha channels, selected pixels appear as white; unselected pixels appear as black
(partially transparent or selected pixels appear as gray). These are the channel default
options.
•
If you display an alpha channel at the same time as color channels, the alpha channel
appears as a transparent color overlay, analogous to a printer’s rubylith or a sheet of
acetate. To change the color of this overlay or set other alpha channel options,
see “
C
r
ea
ting alpha channels (P
hot
oshop)
”
on page
280
.
Changing the display of the palette
You can show the individual color channels in color (rather than grayscale) in the Channels
palette and specify the size of the thumbnails. Using thumbnails is the most convenient
way of tracking channel contents; however, turning off the display of thumbnails can
improve performance.
To show color channels in color:
1 Do one of the following:
•
In Windows and Mac OS 9.x, choose Edit > Preferences > Display & Cursors.
•
In Mac OS X, choose Photoshop > Preferences > Display & Cursors.
2 Select Color Channels in Color, and click OK.
To resize or hide channel thumbnails:
1 Choose Palette Options from the Channels palette menu.
2 Select a display option:
•
Click a thumbnail size. Smaller thumbnails reduce the space required by the palette—
helpful when you’re working on smaller monitors.
•
Click None to turn off the display of thumbnails.
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Selecting and editing channels
You can select one or more channels in the Channels palette. The names of all selected,
or active, channels are highlighted. Any editing changes you make apply to the active
channels.
To select a channel:
Click the channel name. Shift-click to select (or deselect) multiple channels.
To edit a channel:
Use a painting or editing tool to paint in the image. Paint with white to add the selected
channel’s color at 100% intensity. Paint with a value of gray to add the channel’s color at a
lower intensity. Paint with black to fully remove the channel’s color.
Managing channels (Photoshop)
You can rearrange channels, duplicate a channel within or between images, split a channel
into separate images, merge channels from separate images into one new image, and
delete alpha and spot channels when you’re finished with them.
Rearranging and renaming channels
The default color channels normally appear at the top of the Channels palette, followed by
the spot color channels, and then the alpha channels. You cannot move or rename the
default channels, but you can rearrange and rename spot and alpha channels to suit the
way you work.
Spot colors are overprinted in the order they appear in the Channels palette.
To change the order of alpha or spot channels:
Drag the channel up or down. When a line appears in the position you want, release the
mouse button.
Note: You can move alpha or spot channels above the default color channels only if the
image is in Multichannel mode.
To rename an alpha or spot channel:
Double-click the channel’s name in the Channels palette, and enter a new name.
Duplicating channels
You might duplicate an image’s channel to make a backup before editing the channel.
Or you might duplicate alpha channels to a new image to create a library of selections to
load into the current image one by one—thus keeping the file smaller.
If you are duplicating alpha channels between images, the channels must have identical
pixel dimensions. (See “
C
r
ea
ting new images
”
on page
73
.)
Note: You cannot duplicate a channel to a Bitmap-mode image.
To duplicate a channel using the Duplicate command:
1 In the Channels palette, select the channel to duplicate.
2 Choose Duplicate Channel from the Channels palette menu.
3 Type a name for the duplicate channel.
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4 For Document, do one of the following:
•
Choose a destination. Only open images with pixel dimensions identical to the current
image are available. To duplicate the channel in the same file, select the channel’s
current file.
•
Choose New to copy the channel to a new image, creating a multichannel image
containing a single channel. Type a name for the new image.
5 To reverse the selected and masked areas in the duplicate channel, select Invert.
To duplicate a channel within an image by dragging:
1 In the Channels palette, select the channel you want to duplicate.
2 Drag the channel onto the New Channel button at the bottom of the palette.
To duplicate a channel to another image by dragging or pasting:
1 In the Channels palette, select the channel you want to duplicate.
2 Make sure that the destination image is open.
Note: The destination image does not have to be the same pixel dimensions as the dupli-
cated channel.
3 Do one of the following:
•
Drag the channel from the Channels palette into the destination image window.
The duplicated channel appears at the bottom of the Channels palette.
•
Choose Select > All, then choose Edit > Copy. Select the channel in the destination
image and choose Edit > Paste. The pasted channel overwrites the existing channel.
Splitting channels into separate images
You can split the channels of a flattened image into separate images. The original file is
closed, and the individual channels appear in separate grayscale image windows. The title
bars in the new windows show the original filename plus the channel abbreviation
(Windows) or full name (Mac OS). Any changes since the last save are retained in the new
images and lost in the original.
Splitting channels is useful when you want to retain individual channel information in
a file format that doesn’t preserve channels.
Note: Only flattened images can be split. (See “
F
latt
ening all la
y
ers
”
on page
295
.)
To split channels into separate images:
Choose Split Channels from the Channels palette menu.
Merging channels
Multiple grayscale images can be combined into a single image. Some grayscale scanners
let you scan a color image through a red filter, a green filter, and a blue filter to generate
red, green, and blue images. Merging lets you combine the separate scans into a single,
color image.
Note: You can also blend the data in one or more channels into an existing or new
channel. (See “
M
ixing c
olor channels (P
hot
oshop)
”
on page
271
.)
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The images you want to merge must be in Grayscale mode, have the same pixel dimen-
sions, and be open. (See “
C
hanging the pix
el dimensions of an image
”
on page
67
.) The
number of grayscale images you have open determines the color modes available when
merging channels. For example, you can’t merge the split channels from an RGB image
into a CMYK image, because CMYK requires four channels and RGB requires only three.
Note: If you are working with DCS files that have accidentally lost their links (and so
cannot be opened, placed, or printed), open the channel files, and merge them into a
CMYK image. Then resave the file as a DCS EPS file.
To merge channels:
1 Open the grayscale images containing the channels you want to merge, and make one
of the images active.
You must have more than one image opened for the Merge Channels option to be
available.
2 Choose Merge Channels from the Channels palette menu.
3 For Mode, choose the color mode you want to create. If an image mode is unavailable,
it is dimmed. The number of channels appropriate for the mode appears in the Channels
text box.
4 If necessary, enter a number in the Channels text box.
If you enter a number that is incompatible with the selected mode, Multichannel mode is
automatically selected. This creates a a multichannel image with two or more channels.
5 Click OK.
6 For each channel, make sure the image you want is open. If you change your mind
about image type, click Mode to return to the Merge Channels dialog box.
7 If merging into a multichannel image, click Next, and repeat step 6 to select the
remaining channels.
Note: All channels of a multichannel image are alpha channels.
8 When you are finished selecting channels, click OK.
The selected channels are merged into a new image of the specified type, and the original
images are closed without any changes. The new image appears in an untitled window.
Note: You cannot split and recombine (merge) an image with spot color channels. The
spot color channel will be added as an alpha channel.
Deleting channels
You may want to delete spot or alpha channels you no longer need before saving an
image. Complex alpha channels can substantially increase the disk space required for an
image.
To delete a channel (Photoshop):
1 Select the channel in the Channels palette.
2 Do one of the following:
•
Alt-click (Windows) or Option-click (Mac OS) the Trash button .
•
Drag the channel name in the palette to the Trash button.
Documents you may be interested
Documents you may be interested
