Keep Your Eye on the Dropper
The Eyedropper tool samples the color information from an image. But because you've been diddling around and have not really created anything of substance to sample, use File, Open go to the Samples folder of your Photoshop directory and locate the Dune.tif image. If you were retouching an image file or working on a refined painting, you would more likely want to draw your samples directly from the image itself to help create a color harmony. Sometimes, though, sampling the color from a previous image benefits the one on which you're currently working.
Click the Eyedropper tool in the Toolbox. With the Dune.tif file open, choose any section of blue sky to sample some color (see Figure 3.13). The RGB elements that make up the blue you select become the Foreground color.
Figure 3.13 Use the Eyedropper to create exact color matches. On the Options bar, the default is Point Sample, which samples the exact pixel that you click on. You may also choose for the eyedropper to take a 3 pixel by 3 pixel (or 5 pixel by 5 pixel) sample, Photoshop averages the color values and then chooses the closest color to the average.
Drop in Anytime
You can access the Eyedropper instantly when using one of the painting or drawing tools, such as the Airbrush or the Pencil, by pressing the Alt [Opt] key. Press the key, sample a color, release the key, and paint!
The Least You Need to Know
To create very colorful files:
Use the RGB mode for color images, and Grayscale for black-and-white images (except in ImageReady, where every image must be RGB).
Change the color mode only when absolutely necessary, and don't jump back and forth between modes.
Black and white are the default Foreground and Background colors. Press the D key to access them, and press the X key to switch them. Clicking on the Foreground or Background color opens the Color Picker.
You can use the sliders found in the Color palette to change color on-the-fly.
The Swatches palette enables you to be more efficient by giving you a group of colors to choose from.
The Eyedropper tool gives you the power to create color harmony, and can be used by pressing Alt [Opt] when using a painting or drawing tool.