The waterfall of blood, the blood rainbow, humans with green blood, and blood type personalities.
It is a common superstition in Japan that your blood type help to dictate your personality.
At the end of a glacier in Antarctica is a blood-red waterfall.
Under the right circumstances, you can see a monochromatic blood-red rainbow.
Bodily fluids can come in a full rainbow of colours. For example, one common drug has a very rare side effect: green blood.