The settings in the Line settings [Line Settings] menu item relate to the dimensioning view and the variant preview.
Selection The color defined here refers exclusively to the component area that you have marked in the 2D preview using the frame (context menu command: "Selection: Mark section [Selection: Mark region]").
Display all lines thin [Show all lines thin]: Sets thick lines to setting "0.0"
Use colors: If this option is deactivated, all color settings are ignored and replaced by "black".
Display cosmetic elements in a separate color [Use one color for cosmetic elements]: Activates or deactivates the setting for the Cosmetic elements field.