Naval eye - why does the RAF wear blue, your trivia question?
As I recall, the Tsar (of Russia) had ordered some new cloth for his Imperial Guard's uniform, unfortunately there was a revolution & he didn't need the cloth any more. Shortly afterwards the RAF formed, the cloth was going begging, & the RAF's tradition of doing everything on ther cheap was started when it snapped it up - that it was roughly the colour of the sky was only fortuitous.