Tones library can be used for colors storage and for fast access to frequently used colors.
To choose a color it is necessary to fulfill the following operations:
left click on a color pad, as a result a color palette will be opened, and the mouse pointer will change on a dropper;
select a color by one of the following methods:
from the palette, for this purpose you should move the dropper on the graphic palette and select a color by a left-click,
from the color dialog (opens by a click on the color wheel in the right upper corner of the palette),
from an original image or from any other point of the screen, for this purpose you should move the dropper on the screen and select a color by a left-click,
as an averaged color, for this purpose you should select a rectangular area of the image by dragging the cursor while holding the left mouse button and Alt key pressed.
When the color is selected, the color of a color pad will be replaced by the selected one:
You can remove a color by right-click on the color pad.
Besides, it is possible to drag color in the Tones library from a color pad from the Color selection area and vice versa.
Color dragging is carried out as follows:
Left-click on color pad in the library or in the Color selection area
so that mouse cursor changes on 
;
Holding the left mouse button, drag the cursor in the area of the color pad, on which it is necessary to copy the color, and release left mouse button.