By pressing the button, the "Choose The Color" dialog appears. Here you can set the color of the line chart. You have five possibilities for set this color: Swatches, HSV, HSL, RGB or CMYK (see the figures below).
This option sets the width of the line in the chart (the minimum value is 1 and the maximum is 5). You can see two examples below for this option. In the first figure the width of the line is 2, in the second figure is 5.
The prices used for the line chart are: close, low, high and open. By default the price used is close. In the figure below you can see how can you change this option.
"Ok" button - this will change the previous setting with the actual settings
"Cancel" button - the change in setting will be ignored