Occasionally, the state of computer graphics technology reminds me of television in the early 1950s. Only the upper echelon of Photoshop artists can afford to work exclusively in the wonderful world of color. The rest of us have to be prepared to print many or even most of our images in black and white.

Some of you might be thinking, “Wait a second, what about the equalizing force of the Internet? It brings color to all of us!” Well, I concur wholeheartedly. Nearly everyone owns a color monitor, so we can all share color images freely. If this appeals to you.

Regardless of who you are print person or Web head color is a prime concern. Even gray values, after all, are colors. Many folks have problems accepting this premise I guess we’re all so used to separating the worlds of grays and other colors in our minds that never the two shall meet.

But gray values are only variations on what Noah Webster used to call “The sensation resulting from stimulation of the retina of the eye by light waves of certain lengths.” Just as black and white represent a subset of gray, gray is a subset of color. In fact, you’ll find that using Photoshop involves.

Specifying Colors

First off, Photoshop provides four color controls in the toolbox. These icons work as follows:

• Foreground color: The foreground color icon indicates the color you apply when you use the type, paint bucket, line, pencil, airbrush, or paintbrush tool, or if you Alt-drag with the smudge tool.

The foreground color also begins any gradation created with the gradient tool (assuming that you create a custom gradient, not one of the prefab gradients available through the gradient styles pop-up menu).

Photoshop fills any shapes you create with the new shape tool with the foreground color. You can apply the foreground color to a standard selection by choosing Edit>Fill or Edit>Stroke or by pressing Alt+Backspace.

To change the foreground color, click the foreground color icon to display the Color Picker dialog box, select a new color in the Color palette, or click an open image window with the eyedropper tool. You also can set the foreground color by clicking a swatch in the Swatches palette.

• Background color: The active background color indicates the color you apply with the eraser tool. The background color also ends any custom gradation created with the gradient tool. To change the background color, click the background color icon to display the Color Picker dialog box.

Or define the color by using the Color palette, clicking a swatch in the Swatches palette, or Alt-clicking any open image window with the eyedropper tool. You can apply the background color to a selection by pressing Backspace or Delete.

But if the selection is floating or exists on any layer except the background layer, Backspace actually deletes the selection instead of filling it. For complete safety, avoid the Backspace key and use Ctrl+Backspace to fill a selection with the background color instead.

• Switch colors: Click this icon (or press X) to exchange the foreground and background colors.

• Default colors: Click this icon (or press D) to make the foreground color black and the background color white, according to their factory default settings. If you’re editing a layer mask or an adjustment layer, the default colors are reversed.

Using Color Picker

When you click the foreground or background color icon in the toolbox or the Color palette, Photoshop displays the Color Picker dialog box. (This assumes that Adobe is the active option in the Color Picker pop-up menu in the General Preferences dialog box.

If you select the Windows option, the generic Windows Color Picker appears.) Figure below labels the wealth of elements and options in the Color Picker dialog box, which work as follows:

• Color slider: Use the color slider to home in on the color you want to select. Drag up or down on either of the slider triangles to select a color from a particular 8-bit range. The colors represented inside the slider correspond to the selected radio button.

For example, if you select the H (Hue) radio button, which is the default setting, the slider colors represent the full 8-bit range of hues. If you select S (Saturation), the slider shows the current hue at full saturation at the top of the slider, down to no saturation—or gray—at the bottom of the slider.

If you select B (Brightness), the slider shows the 8-bit range of brightness values, from solid color at the top of the slider to absolute black at the bottom.

You also can select R (Red), G (Green), or B (Blue), in which case the top of the slider shows you what the current color looks like when subjected to full-intensity red, green, or blue (respectively), and the bottom of the slider shows every bit of red, green, or blue subtracted.

For a proper introduction to the HSB and RGB color models, including definitions of specific terms such as hue, saturation, and brightness.

• Color field: The color field shows a 16-bit range of variations on the current slider color. Click inside it to move the color selection marker and, thereby, select a new color. The field graphs colors against the two remaining attributes not represented by the color slider.

For example, if you select the H (Hue) radio button, the field graphs colors according to brightness vertically and saturation horizontally, as demonstrated in the first example of Figure below.

The other examples show what happens to the color field when you select the S (Saturation) and B (Brightness) radio buttons. Likewise, Figure below shows how the field graphs colors when you select the R (Red), G (Green), and B (Blue) radio buttons.

Obviously, it would help to see these images in color, but you probably couldn’t afford this big, fat book if we’d printed it in full color. So I recommend you experiment with the Color Picker inside your version of Photoshop.

Slider and field always work together to represent the entire 16 million color range. The slider displays 256 colors, and the field displays 65,000 variations on the slider color; 256 times 65,000 is 16 million. No matter which radio button you select, you have access to the same colors; only your means of accessing them changes.

• Current color: The color currently selected from the color field appears in the top rectangle immediately to the right of the color slider. Click the OK button or press Enter to make this the current foreground or background color (depending on which color control icon in the Toolbox you originally clicked to display the Color Picker dialog box).

• Previous color: The bottom rectangle to the right of the color slider shows how the foreground or background color whichever one you are in the process of editing looked before you displayed the Color Picker dialog box. Click the Cancel button or press Escape to leave this color intact.

• Alert triangle: The alert triangle appears when you select a bright color that Photoshop can’t print using standard process colors. The box below the triangle shows the closest CMYK equivalent, invariably a duller version of the color. Click either the triangle or the box to bring the color into the printable range.

• Web-safe alert cube: Added in Version 5.5, the little cube appears if you select a color that’s not included in the so-called Web-safe palette, a 216-color spectrum that’s supposedly ideal for creating Web graphics.

Know that if you click either the cube or the swatch below, Photoshop selects the closest Web-safe equivalent to the color you originally selected.

Entering Numeric Color Values

In addition to selecting colors using the slider and color field, you can enter specific color values in the option boxes in the lower-right region of the Color Picker dialog box. Novices and intermediates may find these options less satisfying to use than the slider and field.

These options, however, enable artists and print professionals to specify exact color values, whether to make controlled adjustments to a color already in use or to match a color used in another document. The options fall into one of four camps:

• HSB: These options stand for hue, saturation, and brightness. Hue is measured on a 360-degree circle. Saturation and brightness are measured from 0 to 100 percent. These options permit access to more than 3 million color variations.

• RGB: You can change the amount of the primary colors red, green, and blue by specifying the brightness value of each color from 0 to 255. These options enable access to more than 16 million color variations.

• Lab: This acronym stands for luminosity, measured from 0 to 100 percent, and two arbitrary color axes, a and b, whose brightness values range from –120 to 120. These options enable access to more than 6 million color variations.

• CMYK: These options display the amount of cyan, magenta, yellow, and black ink required to print the current color. When you click the alert triangle, these are the only values that don’t change, because they make up the closest CMYK equivalent.

At the bottom of the dialog box, the value next to the pound sign (#) shows you the hexadecimal value for the chosen color. This value comes into play only if you’re creating Web graphics—and maybe not even then.

In Web-land, every color is assigned a numeric value based on the hexadecimal numbering system. Each value includes a total of three pairs of numbers or letters, one pair each for the R, G, and B values. When you create a color tag in HTML code, you enter the hexadecimal value for the color you want to use.

Fortunately, you can now create a Web page without having to write your own HTML code; today’s pagecreation programs do the work for you. But if you prefer to do your own coding you lovable geek, you make note of the hexadecimal value in the Color Picker dialog box.

This option can also come in handy if you want to precisely match a color on an existing Web page. Just look at the HTML coding for the page, note the hexadecimal value in the appropriate color tag, and enter that value in the Color Picker dialog box.