No Black Helicopter

I did this drawing in color pencil after my high school art teacher took away my black color pencil. She said that I used back too often to make shadows and I was over doing it. She wanted me to use contrasting colors to get nice natural looking shadows and shading. So I stopped using black after that day and on this drawing I tried to use no black to draw a black object. (an Apache Helicopter) I think I did a good job from a distance it looks dark but on a closer look there is no black at all in this drawing.

No Black Helicopter