Blue Blood
While the blood in our arteries appears red, the blood that we can see in our veins looks blue. Many people believe that the blood inside is actually blue but gets oxidized after leaving the body and then looks red.
This isn’t true. The blood is in fact always red. When light penetrates the blood exhausted of oxygen in the veins, the blue light is what finds its way to our eyes. The blood in reality is dark red on its way to the heart and bright red when filled with oxygen coming from the heart.