Outlines can show a square colour swatch, including border and pattern information, in the area reserved for the link widget between the note's icon and its badge. Because of the swatch's positioning, when a note with a swatch is selected, the link widget temporarily replaces the swatch.
The main aim of this feature is to allow the display of progress using the 'bar' and 'vbar' patterns that display a progress bar in map note icons.
Swatches are activated via the $OutlineColorSwatch attribute.
From v8.7.0, this feature can be toggled on/off via the Appearance Inspector's Outline tab.