Word before or after "blue" (3)
I believe the answer is:
sky
'word before or after blue' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for sky that I've seen before include "Heavens above!" , "Upper region, empyrean" , "Upper air" , "Hit high into the air" , "Orbiting space-station" .)