Typically a white flag.
white
white
green
The color white is commonly associated with surrender. In some cultures, a white flag is used to indicate surrender during conflicts or negotiations.
The color white is used as a surrender or peace flag.The white flag is an internationally recognized protective sign of truce or ceasefire, and request for negotiation. It is also used to symbolize surrender, since it is often the weaker military party which requests negotiation. A white flag signifies to all that an approaching negotiator is unarmed, with an intent to surrender or a desire to communicate. Persons carrying or waving a white flag are not to be fired upon, nor are they allowed to open fire.
the flag was to show that a play was about to Begin
The white flag is the peace flag, used for truces or surrender. It is not currently the flag of any country. It was previously the flag of the French monarchy prior to 1794, and from 1814 to 1830. The French Navy ensign was likewise white for ships of the line. The plain white flag was most recently used by the Taliban from 1996 to 1997.
Red and yellow are the two most widely used colours on the flag. Though blue is also a colour, though not used as much.
to show the declaration of independence
The tri-colour style is used on many flags around the world. The Irish flag could be said to be based on any of them, such as the French flag.
Today none, it used to be Libya (just green), but when Gaddafi's regime ended another flag was adopted.
In the 'old days' the flag used at the start of the race was white. Though they were used so often they often turned a dingy sort of beige color. Nowadays flag are only used in steeplechases and it is typically still a white flag.