Black Back Drop?

We were thinking to add effect to the sequence the final shot would have a black back drop to add effect, we went out of the classroom to test this and see if it would work well with our piece. This is what we got;

We felt that this shot didn't have the effect that we were hoping for. We felt that the back drop didn't look as black as we would like it because the lights were too yellow. This would be more effective if we had a white light therefore creating more of a contrast in light and dark.
We will try this again for our final cut with a different cloth and a white light rather than a yellow energy saver!