Colors: Red

I know that there are people who can't see at all, and people who can't see all the colors. I'm not grateful enough for the ability to see, and to see color.

Red is a popular color. The Wikipedia has a good article on it. There are positive and negative associations with the color. U. S. stop signs are red. A person who is angry is sometimes described as "seeing red." Teachers often grade papers with red markers. We eat (or don't) red meat.

The national flags of Canada, China, Indonesia, Japan, and the United States all use red, as do those of other countries. That of China, the world's most populous country, is almost all red.

Blood is often described as red. However, only oxygenated blood is red. I've given blood, or had blood drawn, many times, and such blood is dark red, or reddish brown, because it comes from veins, where it has less oxygen. The red cells of blood are very important, although they have basically only one function. That function is to furnish oxygen to the other cells of the body. Hemoglobin is the molecule in red cells that carries oxygen. When oxygen combines with the iron in hemoglobin, the hemoglobin has a red color.

Some of the largest stars are called red giants. They are cooler than most other stars.

Many flowers are red. Red roses, of course, are associated with Valentine's Day.

Bees aren't able to see the color red. (They can see ultraviolet, which we can't see.)

Red in the Bible
The Bible uses red in a number of ways, or to stand for a number of things, as we do today. Here are some of those.

The Israelites crossed the Red sea. The Wikipedia article on that body of water indicates that the name may be a mistranslation of Reed sea, or may be because of seasonal algal blooms of a red color, or may be because of red-colored mountains near it. Over half of the occurrences of "red" in scripture refer to that crossing.

Red was significant in Jewish ceremonial law. God directed that some of the covering of the tabernacle be skins dyed red. (There are five statements about this, from Exodus 25:5 to 39:34.) God specified that a red heifer be used to prepare the water for cleansing those who had been ceremonially unclean (Numbers 19).

Zachariah 1:8 and 6:2, and Revelation 6:4 prophesy about a man riding a red horse, as symbolic of war. The man in Revelation (perhaps also in Zechariah) is one of the Four Horsemen of the Apocalypse.

Isaiah said that though sins were red like crimson, they could be as white as wool. That's interesting, because, in both the Old and New Testaments, blood was used in atonement for sin. So, symbolically speaking, red sin can be washed with red blood, and becomes white!

Red or reddish-brown, Christ's blood was the most precious substance in earth's history.

Infrared
The visible colors are only a small part (less than an octave) of the electromagnetic spectrum. Infrared light is a little redder than red, so to speak. Better put, its waves are of a slightly lower frequency, and a slightly longer wavelength, than red light. Infrared is also called radiant heat.

Some animals are able to perceive infrared light. They aren't able to do this with their eyes, but with other specialized organs. Humans can perceive infrared light with special instruments, which are used in hunting at night, night photography, and in warfare

Red and Valentine's Day
I'm not certain why the color red came to be associated with valentine's day. My guess is that the association is related to the heart, the blood-pumping organ, which is often thought of as the seat of the emotions. The heart isn't really the seat of the emotions, and it doesn't really look like a valentine. It doesn't have a sharp point at one end, and two equal curves at the other. I wonder where the valentine shape comes from. Here's a theory on that, involving a flower.