Google "vittorio storaro color" and you'll find some interesting hits. Also check out "Making Of" on TANGO DVD. Here's an excerpt from a Camera Guild interview:

AC: Is the use of colors symbolic, and if so, are there universal meanings?

STORARO: Color is part of the language we speak with film. We use colors to articulate different feelings and moods. It is just like using light and darkness to symbolize the conflict between life and death. I believe the meanings of different colors are universal, but people in different cultures can interpret them in different ways. In the opening scene, the camera is motionless and there is an absence of color, which is black. During Bulworth's first campaign stop in Los Angeles, he visits a church in a Black community, where the main color in costumes and props is red, a symbol of birth and life. From the church, he goes to a meeting with some Hollywood film producers in a private home. It is a rich setting, where he raises money. Orange symbolizes that feeling of comfort. When he visits an after-hours club, we used yellow, cyan and magenta, the opposites of the three primary colors (red, green and blue) that symbolize daylight. In this scene Bulworth is considering his subconscious feelings. The second day, he goes to the Beverly Wilshire Hotel, where he tells people in his own party what he is thinking. It is the first time he speaks honestly about his feelings in front of his party. They don't expect a politician to tell them exactly what he is thinking. The color yellow symbolizes that he consciously knew what he was doing. During a television debate, we used green to signify knowledge. That was the first time he revealed his feeling in public. One of his campaign workers brings him to her grandmother's house, where he feels safe, believing that the assassin won't find him there. We used blue to signify freedom. Next, he meets a drug dealer, who explains why he uses children to sell drugs. Indigo symbolizes material power. We don't use white in this film until he completes his journey and is a whole person.

AC: How do you deal with the fact that people living in countries with different cultures might interpret the same colors in different ways?

STORARO: Each color has a specific wavelength of energy, which we perceive the same way that we feel vibrations. Even if they aren't consciously aware of it, the audience can feel a difference between high and low wavelengths of energy. They are reacting to that feeling in addition to what they see on the screen.