Background color

Determines the “white” portion of the pattern, and the erase color of the pencil, eraser, and selection tools.

Foreground color

Determines the “black” portion of the pattern, and the lines of the pencil, rectangle, oval, and line tools.

Dropper tool

Sets the foreground color to the color of any pixel. To pick up a background color instead, use the shift key.

Hold down the option key at any time to quickly switch to this tool.

Pattern selector

Determines the pattern used by the bucket and opaque rectange and oval tools.