gloomy vs looking on the black side

gloomy

noun
  • Someone or something that is gloomy or pessimistic. 

adj
  • Suffering from gloom; melancholy; dejected. 

  • Not very illuminated; dim because of darkness, especially when appearing depressing or frightening. 

looking on the black side

How often have the words gloomy and looking on the black side occurred in a corpus of books? (source: Google Ngram Viewer )