The Eyedropper tool is used to set the selected vector graphic shape(s) and/or component(s) foreground/background or stroke/fill colors by pulling the colors from somewhere else in the window.
To change the foreground/background color of a component
Select the object that you want to change.
Select the Eyedropper tool from the group drawing tools on the far right of the Designer.
Select a color from any object on the Root Container of the window and left-click to set the background color and the right-click to set the foreground color. The technique works the same on other components by affecting the component's Fill Paint color property and the Stroke Paint color property.
To exist the Eyedropper, select the Selection Tool (the mouse pointer icon) from the drawing tools menu.