Explain the use of colour in a streetcar named desire?

In A Streetcar Named Desire, the use of color is designed to show the differences between the upper and lower class. While the lower, working class areas are vibrant and rich with a number of colors, they are in stark contrast to the upper-class Blanche and her all-white clothing. This can indicate how the upper class is losing its vitality and energy when compared with the working class.