A little color thought .. a list of colors and the moods they provoke.
I would have to vote for green...
.. for a playing field.
And opponents should all have to wear bright yellow ..
*Blue: A relaxing color. Blue lowers blood pressure, calms, gives a sense of security, and suppresses appetite.
*Red: This color raises the blood pressure, stimulates appetite and conversation and is often associated with excitement.
*Orange: This color stimulates the appetite, is friendly, relaxing and ambitious.
*Green: This is the easiest color for the eyes to focus on for long periods of time. It soothes pain and is associated with optimism.
*Bright yellow: This color is an eye irritant and a highly emotional color. After long periods of time, yellow invokes feelings of anger and hostility. However, yellow, in small doses, is a friendly, happy color.
*Black: This is a powerful, mysterious color and is associated with seriousness.
*Pink: This is a youthful, feminine color. Pink is also a soft, sensitive color.
*Purple: This color is often associated with royalty. It is also a contemporary color.
*Brown: This is an organic, earthy color. It is considered to be heavy and unpretentious.