The blood in our body is indeed red because of a protein called hemoglobin, which carries oxygen throughout our body. However, when we look at our veins through our skin, they often appear blue, purple, or even green. This might seem like a strange contrast, but it raises an interesting question: why do our veins look different from the actual color of the blood inside them? This question was recently explored in the daily podcast "l'édition du soir," where experts and hosts discussed the science behind this visual phenomenon. The discussion aimed to explain what happens between the red blood and the colors we see on the surface of our skin. The answer lies in how light interacts with our skin and the way our eyes perceive color. When light hits the skin, some of it is absorbed, and some is reflected back. Blood in the veins absorbs certain wavelengths of light and reflects others. Our skin also plays a role by scattering the light, which can make the veins appear darker or different in color than they actually are. Although the blood is red, the way it appears through our skin is influenced by multiple factors, including the depth of the veins and the surrounding tissue. This explanation helps clarify why our veins look the way they do, even though the blood inside them is clearly red.