What color is the heart “in love”?

It certainly isn’t as colorful as the diagrams would lead you to believe. The veins and arteries look pretty much the same to the untrained eye.

However, if you were to cut open a major vein you would encounter darker red blood, and if you were to cut open an artery you would find bright red blood. The colors on the model help you learn the heart so that once you encounter the real thing, you can pick out features and vessels.