Color is an important element in art that can convey different meanings and feelings. The document discusses several paintings and how the use of color impacts the overall mood, including Tanner's "Annunciation" where warm orange and yellow colors represent happiness, and Picasso's "Old Guitarist" where various shades of blue create a gloomy feeling for the subject. It also examines works by Monet, David, and Pollock and how colors were used in each to convey calmness, cruelty, and tranquility respectively.