A more thorough explanation:

Definition: A color book is an old-fashioned term used in international law to refer to an official collection of diplomatic documents, internal papers, and reports of a government. The primary purpose of a color book is to inform the legislature and the public about foreign policy, especially during foreign crises. Color books were popular in the late 19th and early 20th centuries, but they are now rarely used in most countries.

Example: During the Cuban Missile Crisis in 1962, the United States government created a color book to provide information to Congress and the public about the situation. The color book contained classified documents, intelligence reports, and other information related to the crisis.

Explanation: The example illustrates how a color book was used during a foreign crisis to inform the government and the public about the situation. The color book contained important information that was necessary for making decisions and understanding the foreign policy implications of the crisis.