Romeo is normally very melancholic. When he sees Juliet at the party, however, he appears more sanguine
The definition of sanguine is positive and hoping for good things.
Romeo Montague is the male main character of William Shakespeare's The Tragedy of Romeo and Juliet. He is son of Lord Montague and his wife, Lady Montague. He secretly loves and marries Juliet, who belongs to the rival House of Capulet, through a priest called Friar Laurence.