Cortland I have seen white with Green Spec and Natural (off white) 9/27. I think it is important to keep in mind Cortland is the manufacturer, and the 9/27 was a line size and weight. 9/27 was made by just about every linen company. Ashaway, Cortland, Halls,, US Line, there was probably 200 manufacturers of flax, cuttyhunk linen.
I have a great spool of green, very nice from Halls. I have seen green with white spec, and I was told someone had white with black spec. I would imagine that brown could be found.