Claim: Blood is blue inside your body

The claim that blood is blue inside your body is false. Mainstream medical sources consistently affirm that all human blood is red, regardless of oxygenation levels. They explain that the blue appearance of veins is due to light scattering through the skin, not the actual color of the blood itself. Some alternative sources may suggest otherwise, but they lack scientific backing and clarity on the optical phenomena involved. All three graders point in the same direction, with minor differences. OpenAI comes in highest (10%), while Gemini is lowest (0%). There are no credible opposing sources that support the claim that blood is blue inside the body. The consensus among medical professionals and scientific literature is clear that blood is always red, and any perception of blue is an optical illusion caused by how light interacts with skin. This overwhelming agreement among experts reinforces the certainty of the verdict, leaving little room for doubt or alternative interpretations.