It's blood. Under the veins from outside it appears blue because only light close to the wavelengths of blue are strong enough to penetrate that deep and reflect back at our eyes.
I wear a green jacket on the outside, white jacket as a second layer, and red jacket inside. I am pregnant with a lot of babies. What am I?
When you prepare me for dinner you take off my outside and cook my inside.When you eat me, you eat my outside and throw away my inside. Who am I?
