Cubism is a more modern art movement in which forms are abstracted by using an analytical approach to the object and painting the basic geometric solid of the subject
In the earlier years, cubism was quite limited to only few shades and colours, black, brown, gray and white shades <===(check up on that im not sure if there were any more)
Later on in 1920s (arround that time) more colours were introduced to cumism, and it was painted in more of a symetrical way.
What exactly ON cubism do you wanna know....Synthetic cubism??? Picasso???Braque??
Be more specific adn i'll help you write an essay if you wish.