As a user I’m able to connect two shapes by a connector that has two colours*, so that I can also see it if the connecter runs across differently coloured backgrounds (without having to change the colour scheme preferred). *For instance by giving it also a contour colour or shadow colour (which is in essence shifting a contour). Example: An arrow that is white in a colour scheme of black and white. It would in this scheme benefit to have as a second colour black as either contour or shadow. Interface could be similar as for outline and fill of shapes, so familiar for current users.
