Photoshop cs5 by steve Johnson part 30 pps

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Chapter 8 Understanding Colors and Channels 187
The Duotone Color mode converts a grayscale image into a monotone
(1-color), duotone (2-color), tritone (3-color), or quadtone (4-color)
image using 1 to 4 custom inks. Duotones are frequently used to
increase the tonal depth of a grayscale image. For example, most print-
ing presses produce 50 levels of gray per color. By converting an image
into a duotone, and using black and a mid-gray value, the press can
produce a grayscale image with more dynamic range. A more common
method for employing the Duotone color mode is to create an image
with an overall color cast, for example, by converting the grays in the
image to a sepia tone. If you're uncertain how to create the proper
color mix for a duotone image, Photoshop comes equipped with dozens
of sample duotone, tritone, and quadtone color presets.
Understanding the
Duotone Color Mode
Convert an Image to Duotone
Open an image. Click the Image
menu, point to Mode, and then
click Duotone.
IMPORTANT
Before converting
an image into a duotone, it must
first be in the Grayscale color
mode.
Choose from duotone presets
available in the Preset drop-down
menu. Choose to save or load a
preset by clicking on the menu
options triangle to the right of the
preset menu.

Click the Type list arrow, and then
select from the following options:
◆ Monotone. Uses one color to
generate image tone (limited
dynamic range).
◆ Duotone. Uses two colors to
generate image tone (better
dynamic range for B&W
images).
◆ Tritone. Uses three colors to
generate image tone.
◆ Quadtone. Uses four colors to
generate image tone.
Click the Overprint Colors button to
adjust how the colors will display
when the inks are printed.
Click OK.
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Duotone color
mode
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From the Library of Wow! eBook

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188 Chapter 8
The Multichannel color mode is a specialized mode that converts the
original color channels into shades of gray, with the grays based on the
luminosity values of the original image. The original channels are con-
verted into spot colors. Since Multichannel mode is used almost exclu-
sively by the printing industry, converting a CMYK image into
Multichannel color mode produces Cyan, Magenta, Yellow, and Black
spot channels, and converting an RGB image into Multichannel mode
produces Cyan, Magenta, and Yellow spot channels, minus the Black
channel. In both instances, converting to Multichannel Color mode
causes the loss of the Composite channel.
Using Multichannel
Color Mode
Use the Multichannel
Color Mode
Open an image.
Click the Image menu, point to
Mode, and then click
Multichannel.
Photoshop converts the image
into the Multichannel mode.
IMPORTANT
Images
converted to the Multichannel
mode must be saved in the DCS 2.0
format (Desktop Color
Separations). The DCS 2.0 format
generates a separate file for each
of the image’s spot colors.

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The Multichannel
panel minus the
Composite channel
See Also
See “Preparing an Image for the
Press” on page 402 for more informa-
tion on saving an image in the DCS 2.0
format.
From the Library of Wow! eBook
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Chapter 8 Understanding Colors and Channels 189
Photoshop's Replace Color command lets you create a selection based
on image color, and replace that color selection with any other color.
The Replace Color adjustment accomplishes this by giving you access
to the three components of color: Hue, Saturation, and Brightness. Hue
gives you the ability to change the image's actual color, Saturation con-
trols the amount of color, and Brightness determines how bright the
color is based on its Hue and Saturation.
Using the Replace
Color Adjustment
Use the Replace Color
Adjustment
Open a color document.
Click the Image menu, point to
Adjustments, and then click
Replace Color.
Select the Localized Color

Clusters check box if you want to
limit your color selection to a
specific area on the active
document, using the Selection
eyedroppers to select, add, or
subtract colors.
Click the Color box to select a
specific color for the selection.
Drag the Fuzziness slider to
increase or decrease the
sensitivity of the eyedropper tools.
Click the Selection or Image
option to toggle between a view of
the selection mask and the active
image (white areas of the mask
represent selected areas).
Drag the Hue, Saturation, and
Lightness sliders to change the
selected areas.
Select the Preview check box to
view the changes in the active
document.
Click OK.
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From the Library of Wow! eBook
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190 Chapter 8
Photoshop not only lets you select virtually any colors you desire, it
also lets you store those colors for future use. For example, you create
a color scheme for a recurring brochure and you want a way to save
those colors, or you're working on an Internet graphic and you need a
web-safe color panel. Whatever your color needs, Photoshop stands
ready to meet them. The Color panel gives you access to Photoshop's
color-generation tools. This single panel lets you create colors using 6
different sliders, 2 spectrum color selectors, a grayscale ramp, and an
option that lets you create a color ramp for the current foreground and
background colors.
Working with the
Color Panel
Work with the Color Panel
Select the Color panel.
Click the Color Options button.
Select from the following Color
Sliders:
◆ Grayscale. Creates a single

slider going from white (0) to
black (100).
◆ RGB. Creates three sliders (red,
green, and blue). Each slider
has a possible value from 0 to
255.
◆ HSB. Creates three additive
sliders (hue, saturation, and
brightness). Each slider has a
possible value from 0 to 255.
◆ CMYK. Creates four subtractive
sliders (cyan, magenta, yellow,
and black). Each slider has a
possible value from 0 to 100.
◆ Lab. Creates three sliders
(L, a, and b). The L slider has a
possible value from 0 to 120,
and the a, b sliders have a
possible value from -120 to 100.
◆ Web Color. Creates three
sliders (red, green, and blue).
Each slider has a possible
hexadecimal value from 00
to FF.
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From the Library of Wow! eBook
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Chapter 8 Understanding Colors and Channels 191
Click the Color Options button, and
then select from the following
Spectrums or Ramps:
◆ RGB. Converts the lower
portion of the Color panel to the
RGB spectrum. Clicking
anywhere in the spectrum
changes the active color.
◆ CMYK. Converts the lower
portion of the Color panel to the
CMYK spectrum. Clicking
anywhere in the spectrum
changes the active color.
◆ Grayscale. Converts the lower
portion of the Color panel to a
grayscale ramp. Clicking
anywhere in the ramp changes
the active color.
◆ Current Colors. Converts the
lower portion of the Color panel
to a color ramp, using the
current foreground and
background colors. Clicking
anywhere in the ramp changes
the active color.
To re stri ct the color ra mp to
only web-safe colors, click the

Color Options button, and then
click Make Ramp Web Safe.
To ch ange a col or using the Ad obe
Color Picker, double-click a color
box, select a color using the color
range or color mode options, and
then click OK.
You can choose colors using four
color models: HSB, RGB, Lab, and
CMYK.
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Select options or click the color
range to select a color.
Cube indicates the color is not web-safe; click to select the closest web color.
An alert triangle indicates the color is out of gamut (non-printable).
Understanding Spectrums and Ramps
Spectrums and Ramps are located at the bottom of the Color panel,
and represent the entire spectrum for the chosen color space. For
example, the CMYK spectrum displays a rainbow of colors in the
CMYK color gamut. Moving the eyedropper into the spectrum box
and clicking lets you select any color and gives you a visual repre-
sentation of the relationships between various colors. The Grayscale
Ramp gives you linear access to the 256 available grayscale values.
For Your Information
From the Library of Wow! eBook

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192 Chapter 8
Photoshop not only lets you select virtually any colors you desire, it
also lets you store those colors for future use in a library of color
swatches, the Swatches Panel. Where the Color panel lets you select
virtually any color you need, the Swatches panel lets you save and use
specific colors that you use often. By default, the Swatches panel holds
over 30 predefined color swatches, and has the ability to save as many
user-defined swatches as you desire.
Working with the
Swatches Panel
Add a Color Swatch to the
Swatches Panel
Select the Swatches panel.
Click the Swatches Options
button, and then choose from the
predefined color swatches.
Click the Append button to add the
selected color swatch to the
panel.
Change and Delete Colors on
the Swatches Panel
Select the Swatches panel.
Select a color, and then change
the following:
◆ Foreground. Change the color
by clicking on any color in the
Swatches panel.
◆ Background. Change the color
by holding down the Ctrl (Win)

or A (Mac) key, and then
clicking on any color in the
Swatches panel.
◆ Delete. Hold down the Alt (Win)
or Option (Mac) key (your
cursor will turn into a pair of
scissors), and then click the
color in the Swatches panel.
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From the Library of Wow! eBook
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Chapter 8 Understanding Colors and Channels 193
Add Colors to the Swatches
Panel
Select the Color panel, and then
drag the sliders or enter values to
create a new color swatch.
Select the Swatches panel, and
then drag the lower right corner to
expand its size beyond the range
of the available colors.
Move the cursor just below the

last swatch color until it resembles
a paint bucket.
Click once, name the color, and
then click OK.
Save Customized Swatch Panels
Select the Swatches panel.
Create a customized swatch panel
by adding and/or deleting colors
from an existing panel.
Click the Swatches Options
button, and then click Save
Swatches.
Enter a name in the Save As box.
Click the Save In (Win) or Where
(Mac) list arrow, and then select a
location to store the swatch.
Click Save.
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Did You Know?
You can access your customized
swatches from the Swatches Options
button.
When you save swatches in the
Color Swatches folder (default loca-
tion), your customized swatches
appear at the bottom of the Swatches
Options menu.
From the Library of Wow! eBook