Is this question comes.
Under normal light, blood appears red because most colours are absorbed except for red, which bounces back from the blood. Every colour but red is absorbed by the oxygen-carrying pigment haemoglobin (Hb). If a filter that blocks the reflected colour is positioned between the blood and the eyes of the person looking at the veins, the perceived colour changes. In the case of humans, the skin serves as a filter for the colour red, and the colour is therefore perceived as green. The exact colour spectra is determined by the relative levels of oxygenated iron (HbO) and carbon dioxide in the blood. High levels of oxygen reflect red, and high levels of carbon dioxide reflect blue, which, when mixed with the yellowish colour of fat and or the skin, end up looking green .
Under normal light, blood appears red because most colours are absorbed except for red, which bounces back from the blood. Every colour but red is absorbed by the oxygen-carrying pigment haemoglobin (Hb). If a filter that blocks the reflected colour is positioned between the blood and the eyes of the person looking at the veins, the perceived colour changes. In the case of humans, the skin serves as a filter for the colour red, and the colour is therefore perceived as green. The exact colour spectra is determined by the relative levels of oxygenated iron (HbO) and carbon dioxide in the blood. High levels of oxygen reflect red, and high levels of carbon dioxide reflect blue, which, when mixed with the yellowish colour of fat and or the skin, end up looking green.
Yellow +blue=Green