For more, see Project Settings
To activate: File menu / Settings
Configure the color GeoSync uses to highlight selected features.
To use:
Open Settings dialog.
On the General tab, locate the Selection Color field.
The default selection color is yellow. To change the color, click on the far right side of the field to the right of Selection Color.
A triple dot button appears. Select the button. The color palette appears.
Select a color from the palette.
Select OK.