Are you blue or green?

Human blood is never blue. The bluish color of veins is only an optical illusion. Blue light does not penetrate as far into tissue as red light. where it is absorbed by hemoglobin, so whenever you see blood outside your body, it looks red.

Human blood is red because of the protein hemoglobin, which contains a red-colored compound called heme that is crucial for carrying oxygen through your bloodstream. The shorter wavelength of blue means that it doesn’t travel as far as red, thus it doesn’t travel as deep under your skin as the red does. In short, the shorter wavelength that “makes it back to your eye is the blue light.” Genetics play a role in the color of your veins. Some people may naturally have veins that appear bluer, while others might perceive theirs as green.

The degree of transparency and the amount of subcutaneous fat can also affect how veins are seen through the skin. When stressed, your body releases hormones that increase your blood pressure. This can strain your veins, making them more likely to bulge and become varicose. The perception of vein color, whether green or blue, varies among individuals and is influenced by factors like skin tone, light absorption, and genetic predisposition. It’s essential to remember that the actual color of veins is not blue or green; it’s a result of how light interacts with your skin and its underlying structures.