If the art can be group group it and then in the appearance panel while you have all the art add a stoke to it from the flyout menus and the change the color at will. If you want the outline around the whole art only then drag the stroke in the appearance panel below the content.
or you could use the offset path function...
go to Oject - Path - select offset path. In the window type in the amount wider you want the new path/object. It will redraw outside your path in direct proportion (or if you choose a negative value inside your path).
this is a handy tool for that sort of stuff.