buoyancy vs rose-colored glasses

buoyancy

noun
  • Resilience or cheerfulness. 

  • The ability of an object to stay afloat in a fluid. 

  • The upward force on a body immersed or partly immersed in a fluid. 

rose-colored glasses

noun
  • An optimistic perception of something; a positive opinion; seeing something in a positive way, often thinking of it as better than it actually is. 

  • Used other than figuratively or idiomatically: see rose-colored, glasses. 

How often have the words buoyancy and rose-colored glasses occurred in a corpus of books? (source: Google Ngram Viewer )