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I heard something about it turning red when it hits air.

That's not true. If your blood turned red when it hit the air, that would mean your blood wasn't carrying oxygen to the various parts of your body and you would die. Blood is always red.

Veins carry deoxygented blood to the lungs, but it's not actually blue, it's just a deeper shade of reddish purple.

Blue is only the oxygen takin out of your veins.........after it's been used up.........or is that red??..........hmm

blood has iron and other minerals in it.

Oxygen makes it Red.
Carbon Dioxide makes it Blue.

I think.

When haemoglobin is oxygenated it's red and when it's deoxygenated it's purplish (as silver_tears mentioned) so that would make blood as a whole that colour too.

What about when it goes green?

See a doctor

Blood is NEVER blue.. It is dark red when in the veins (going to the heart) and bright red when in the arteries(going away from the heart). Veins look blue because we are looking at them through our skin.

Originally posted by T.M
Blood is NEVER blue.. It is dark red when in the veins (going to the heart) and bright red when in the arteries(going away from the heart). Veins look blue because we are looking at them through our skin. red + peach = blue?

When I look at mine they are blue. When I'm tanned, they seem grey.

Veins are blue!

when you get a blood sample, the blood is pulled into an airtight thing, (i think)

and it's red. Besides, I asked a doctor and it is deffinately red.

Plus, oxygen doesn't make it red. I think it's hemoglobin or something with an unneseccarily complicated name.

It is definitely RED! Appears blue but it is a dark dark red.

Your heart pumps oxygenated blood via arteries, through your body (red). After cellular respiration takes place, there is no more oxygen in the blood, it is now deoxygenated. (dark red with a purplish shade) The veins carry this blood to the heart, and then through the pulmonary artery to the lungs where it ges reoxygenated. The pulmonary vein takes it back to the heart to be yet again pumped through the body as bright red oxygenated blood.

Hemoglobin is a pigment which turns bright red in the prescence of oxygen.

Veins appear blue because light, penetrating the skin, is absorbed and reflected back to the eye. Since only the higher energy wavelengths can do this (lower energy wavelengths just don't have the strength to get in and out), only higher energy wavelengths are seen. And higher energy wavelengths are blue/Violet in colour. (red is at the lower end and cant get back out)


In an experiment, glass tubes were filled with blood and immersed in milk, milk having a similar ratio of fat, proteins, and water in emulsion as skin. At a certain depth, the tubes appeared blue.

Originally posted by T.M
Veins appear blue because light, penetrating the skin, is absorbed and reflected back to the eye. Since only the higher energy wavelengths can do this (lower energy wavelengths just don't have the strength to get in and out), only higher energy wavelengths are seen. And higher energy wavelengths are blue/Violet in colour. (red is at the lower end and cant get back out)


In an experiment, glass tubes were filled with blood and immersed in milk, milk having a similar ratio of fat, proteins, and water in emulsion as skin. At a certain depth, the tubes appeared blue.

This is correct. Oxygenated blood is a bight vivid red. Deoxygenated blood is a deep maroon.

For those you still do not believe/understand:

In the light, blood appears red because most colors are absorbed except for red, which bounces back from the blood. Every colour but red is absorbed by the oxygen-carrying pigment hemoglobin (Hb). If a filter that blocks the reflected color is positioned between the blood and the eyes of the person watching, the perceived color changes. In the case of humans, the skin serves as a filter for the color red, and the remaining color ends up being green. The exact color spectra is determined by the relative levels of oxygenated iron (HbO) and CO2 in the blood. High oxygen reflects red and high CO2 reflects blue, which mixed with the yellowish color of the fat and/or skin ends up showing as green.

http://en.wikipedia.org/wiki/Vein