Why's all of Red's stuff first?
But I do agree... they need those in there. I figure the Dulles line stuff would go to Silver. (You said it was to be Loudon County to Stadium-Armory, right?)
Purple? I'd had an idea for that, but WAY too long... BWI to Woodbridge; some segments of new construction (follow totally new alignment between Greenbelt and the CSX/MARC/Amtrak ROW near Eastern Avenue, with a stop in Riverdale, and one at the District Line) in MD and in DC (under NJ Ave and West Capitol Street between Union Station and L'Enfant Plaza; new stop: Capitol North (original, no?)). Follow Fenwick Bridge (Yellow line) into VA, and then Blue route (L & something, right?) to Fran-Spring... line beyond Fran-Spring would follow Amtrak ROW throuh Newington (station here), Lorton (station here between VRE stop and Auto Train Terminal; includes facing point/trailing point crossover combo (a la Takoma/Silver Spring/Cheverly) before entering from north), and into Woodbridge (turnback station with island platform and X crossover (before entering station from north) + rear tail and pocket tracks; located near Amtrak/VRE station, possibly underground)