#27 Blood Appears Blue When Deoxygenated
Take a gander at your wrist and you’ll understand why some people believe that their blood might be blue. There’s no denying in the fact that our blood is red. It contains haemoglobin which contains iron. Iron reacts with oxygen which gives blood its red colour.
Though the veins appear blue or purple, it has nothing to do with the colour of blood. Freshly-pumped blood from the heart carries a relatively rich hue of red as compared to the deoxygenated blood that is transported back to the heart.
Regardless of the oxygen level in the blood, it can never appear blue. The blood travelling towards the heart appears darker owing to the manner in which the light passes through the skin.