Mannerism, was a colorful artistic style, using vibrant, bright colors, which was highly regarded after the period of the High Renaissance. It is epitomized by the highly stylized and technical works of Michelangelo Buonarroti and Raphael, which stylized the human anatomy and emphasized their muscles. (Art History - Byzantine to Romanticism to Op Art to Modern Art - History of Art; http://www.masters-gallery.com/04_History/04_HistoryTXT.html)
During the Mannerist period, architects experimented with using architectural forms to emphasize solid and spatial relationships. The Renaissance ideal of harmony gave way to freer and more imaginative rhythms. The best known architect associated with the Mannerist style was Michelangelo, who is credited with inventing the giant order, a large pilaster that stretches from the bottom to the top of a facade. He used this in his design for the Campidoglio in Rome. Prior to the 20th century, the term Mannerism had negative connotations, but it is now used to describe the historical period in more general non-judgmental terms In Italy, a new style emerged called Mannerism. Italian artist experimented with spatial sense and proportions in order to express the actions in the painting more beautifully. One artist in Italy, Titian, was a master at using color.