A white flag used to be the flag of France: https://commons.wikimedia.org/wiki/File:Flag_of_France_(1814...
A world flag should not use flags which were associated with a country. Evan this proposal is too derivative of the Japanese flag.
A world flag should not use flags which were associated with a country. Evan this proposal is too derivative of the Japanese flag.
Nevertheless, I think the Earth flag should include the moon too. A blue Earth, a white Moon, and a black background. When the Moon secession war starts, the laser holes in the flag could double as the starry sky.