Palette Window:

You can select a color you like by clicking.

This is a selected background color.

This is a selected line color.

This is a selected foreground color.

Background Color Button:

Use this button to set the color of background.  You can do the same with Tab key

Line Color Button:

Use this button to set the color of line.  You can do the same with Tab key

Foreground Color Button:

Use this button to set the color of foreground.  You can do the same with Tab key.