Dealing with Foreground and Background Colors in Photoshop

Photoshop has two categories of color — a foreground color and a background color. You apply the foreground color when you use the type tools, the painting tools, or the shape tools. It is also the beginning color of a default gradient applied by the Gradient tool. The background color is the color you apply with the Eraser tool (assuming you don’t have layers) and is the ending color of the default gradient. When you increase the size of your canvas, you fill the additional canvas with the background color (also assuming you don’t have layers). You find the swatches that represent the two color categories in the lower part of the Tools palette (also known as the Toolbox).

The default color for the foreground is black; the background is white. Click the small icon to return the colors to the defaults or simply press the D key. That’s easy to remember. To switch the foreground and background colors, click the curved arrow in the Toolbox or press the X key.

Here are a few tips about using tools with foreground and background colors:
-->Use the Brush tool or the Pencil tool with the foreground color. These tools always apply the foreground color.

-->Blend the foreground and background with the Gradient tool. When you drag with the Gradient tool across the canvas and the gradient is set to the default, you get a blending of the foreground and background colors.

-->Fill selected areas with the foreground color. Just click your canvas with the Paint Bucket tool to select areas based on a Tolerance setting and fill those areas with the foreground color.

-->Apply the background color by erasing. If you are working on a background rather than a layer, you can use the Eraser tool to apply the background color. Some people prefer to say you are erasing to the background or canvas color. If you use the Eraser tool on a layer, you erase to transparency. See Book V for the scoop on layers.

-->Use the Shape tools to create shapes that are filled with the foreground color. Simply create the shape, and voilà.

-->Add more background to your canvas and fill it with the background color. When you enlarge your canvas size, Photoshop automatically fills the added canvas with the background color.
If you enlarge a layer, the extra canvas is transparent.