Misc: In 1933 Roman Polanski director (Knife in the Water, ---------- , Macbeth), born. ?

Questions

in military terms, what is the opposite of 'advance'?

in mirc, what colour does control-4 give?

in motor racing, what is yellow?

in music, instrumental introduction to an opera or other musical or nonmusical dramatic work?

in music, the art of extemporization or creating all or part of a composition at the moment of performance?