What do the colors red, white, and blue stand for in the American Flag?
Writers and speakers often attribute meaning to the colors of the flag. But, in truth, the Continental Congress never spoke about what the colors represented.
Still, the red, white, and blue colors included in the Great Seal of the United States, which first appeared 1782, did purportedly represent ideals and beliefs of our Founding Fathers.
Their significance was explained by Charles Thompson, Secretary of the Continental Congress, and included in the book "Our Flag," published in 1989: White represents purity and innocence; red represents hardiness and valor; and blue represents vigilance, perseverance, and justice.
—The Fact Monster