Enhancing Images > Using the Tool Box Toolbar > Using the Painting Tools > Using the Brush Toolbar
To use the Foreground/background color picker tool:
Click the upper-left corner of the button to select a foreground color.
Click the lower-right corner of the button to select a background color.
On the image, click and drag to apply the foreground color.
Right-click and drag to apply the background color.
For information on changing the default colors, see Setting Paintings Preferences.
Using the Size and Density Sliders