This is the time it takes for the first visual image to make it to the brain and to be processed.
They become bonded chemically even if it isn't a good fit otherwise.
Information from the brain creates that initial intense “chemistry” reaction for six months to three years, depending on the person.
Some people are able to maintain the spark for years, whereas others need to move on and find new love to have the "chemistry." Some things to do to keep the spark burning are to send each other love notes, emails and silly pictures of over the phone.
From this, it was created the unique blue dye that archaeologists found in Egypt, Mesopotamia, Crete, and Santorini.
As read in Wikipedia, in the art and life of Europe during the early Middle Ages, blue as a colour had no important role.