blue sky —(also: blue skies)
1. said of impractical or unfeasible plans and ideas:
- The rocket was dismissed as just another bluesky project when the concept was unveiled.
2. (U.S. stock market) is used of fake or worthless bonds and stocks:
- They were what I would term “blue sky and hot air” securities.
sky blue—a deep somewhat purplish blue color:
- The flag on one side of the building was sky blue; the one on the other side was the somewhat darker shade…