Frank J. Wilstach, comp. A Dictionary of Similes. 1916.

Crimson

As crimson as August heather.
—Alfred Austin

Crimson as a comic opera climax.
—J. Cheever Goodwin

Crimson, as if blood were mingled in it.
—Henry W. Longfellow

Crimson, like a sea of blood
Untroubled by a wave.
—John Greenleaf Whittier