what is the color of blood?

Answer 1

Human blood is ALWAYS red. Really. Anyone who says it's blue is mistaken.

This is plainly obvious if you ever donate blood. Phlebotomists always take blood from veins, they are required to do it without exposing it to air, and it always looks red. Likewise, any surgeon (or sausage company) will tell you that all veins and arteries are pretty much clear.

Now, I know what some of you are thinking: 'Wait a minute - I can see some of my veins and they are clearly blue!'. It's okay. There are scientists who have wondered about that too:

In a recent piece of research, it was discovered that veinous blood looks blue only because it's surrounded by much redder blood. They could even reproduce the effect by surrounding red veinous blood with a pool of red oxygenated blood... the veinous blood looked blue when submerged!

And so it goes with other colours as well. Many people have pigments in their skin that can alter the apparent colour of veins and arteries underneath. But this hardly means that the blood actually IS different colours!

There are creatures in the world that do not have red blood - some have greenish-blue blood because they use copper atoms to attract oxygen instead of iron. It doesn't work anywhere near as well, unfortunately for all the octopi and mollusks out there.

Answer 2

Venous blood is very dark, purplish. Arterial blood is very red.

No matter how you mix, submerge or whiten something that is red, it will NEVER appear blue. Perhaps people who believe that should go back and study their primary colours.

Blood tests and what not are not done is a vacuum. If the bag you fill to donate blood were truly a vacuum, you would need more than your own blood pressure to over come atmospheric pressure to fill the bag.

Arterial blood is purplish. When you see it the red factor has been filtered out, so you see BLUE! This principle is covered in about grade 2 art class and then again in like grade 12 physics.

Answer 3

In humans and other hemoglobin-using creatures, oxygenated blood is bright red. This is due to oxygenated iron in the red blood cells. Deoxygenated blood is a darker shade of red, which can be seen during blood donation and when venous blood samples are taken. However, due to skin pigments, blood vessel coverings and an optical effect caused by the way in which light penetrates through the skin, veins typically appear blue in color. This has led to a common misconception that venous blood is blue before it is exposed to air. Another reason for this misconception is that medical charts always show venous blood as blue in order to distinguish it from arterial blood which is depicted as red on the same chart.

The blood of horseshoe crabs is blue, which is a result of its high content in copper-based hemocyanin instead of the iron-based hemoglobin found, for example, in humans.

Answer 4

In humans? Red...it comes from the heme (iron) in your blood. You may have heard people say that your blood is blue until it hits the air....this is FALSE.

Blood appears to be blue in your veins because of the color of your veins (white) and gives the bluish appearance.

Answer 5

Blood is so dark it's almost black when it's in our bodies. Exposure to oxygen makes it red.

Answer 6

Blood is blue, but it looks red because when you see it, it has come in contact with oxygen in the air. The oxygen is what makes it turn red.

Answer 7

blue or red depends how muchoxygen it has in it