What is the color of blood?

Question

People say it's red, blue and green. So what is it?

Answer 1

It's actually clear; red blood cells make it look red.

Answer 2

I'm surprised to find so many people ignorant in this matter!

Arterial blood is bright red, veinous blood is a darker hue of red. As someone pointed out, try donating your blood. They take out your veinous blood and you can actually see that it's not blue (and as some of you may argue, it does not come in contact with air!).

The exact colour of blood depends upon the relative levels of oxygenated iron (HbO) and CO2 in the blood. The higher the CO2 percentage, the more bluish it tends to become.

However, the blood in veins does not have CO2 in that high concentration. So deoxygenated blood in veins is a darker hue of red. It appears blue when you look at it through skin because the light reflected by the blood has to pass through fat deposits and the skin before entering your eyes, so it creates an optical illusion.

Answer 3

In animals that make use of hemoglobin (an iron-containing protein in red blood cells that transports oxygen from the lungs to the rest of the body), oxygenated blood is bright red due to oxygenated iron in the red blood cells. Deoxygenated blood is a darker shade of red. However, due to an optical effect caused by the way in which light penetrates through the skin, veins typically appear blue. This has led to a common misconception that blood in the veins is blue before it is exposed to air.

Answer 4

It does depend on the creature.

In humans, blood is made mostly of plasma, which is a clear fluid. The red color comes from the oxygen rich blood cells

Answer 5

It is a common misconception that un-oxygenated blood is blue. Anyone that has ever given blood knows this!

When you give blood the needle is inserted into your veins (veins carry un-oxygenated blood). When the plunger is pulled back it cerates a VACUUM which draws the un-oxygenated blood into the syringe. NOTE: A vacuum has NO oxygen! This blood is red!

Oxygenated human blood is bright red.
Un-oxygenated human blood is a darker RED!

Answer 6

The color of blood is different for every organism. In humans it is red, but some flies have green blood.. i know, gross.

Answer 7

All iron based creatures, like us, have red blood.
The colorization is due to the fact that our blood uses iron to carry oxygen. What you see (to put it plainly) is rust.

Other animals, like certain crabs and lobsters, have bluish/greenish blood. Their bodies use copper as an oxygen carrier.

If you look at human blood under a microscope, it is actually yellow.

So the color of blood depends on what blood it is, and how closely are you looking at it.

Answer 8

The correct answer is silver. When the red blood cells dilate and combine with the lipids in the blood stream they create a process known as coagulation which creates the color silver in the bloodstream.

Answer 9

+ Blood in humans is bright red if it is arterial, dark redish brown if venous. If you are so interested go to a hospital and look or maybe a blood donation center and give a little. You might save a life, and the life you save might find the cure to cancer or something.

The color might be different if you were looking at it in a different solar system and the light filtering UV and In-fa red rays from that planets sun were different. but here on earth it is red.

Answer 10

My mom's a science teacher and says it's blue until exposed to oxygen then it turns red. Now that's for human blood it may be different for animals and crustaceans.