Simulated threads are known as "green threads" in programming-language-wonk speak. They are compared to "native threads" as provided by the operating system, but is there an analogous colour for native threads, and what is it?
User-mode threads can be referred to as "green" threads, whereas kernel-mode threads can be referred to as "red" threads. This terminology is rarely used, but an appreciation of the difference is a good thing to know.
No, there isn't. The "green" is like in "green peace", not like in "green apple". I guess the opposite might be "smoggy" or any other term denoting non-eco-friendliness.
how about "taste" instead of color -- native threads can be "bitter threads" :)
I hope that this is not too far afield. Colors do not have 'opposites' they have complements. The complement of green is magenta.