Why our blood is red in color?

Have you ever amazed why our blood is red in color? Why not some other colors? What is the reason behind that? Actually blood is a connective tissue. It is composed of liquid plasma, Red Blood Cells, White Blood Cells and platelets. It acts as a transporting medium for oxygen and nutrients to each and every single cell of the body. Red blood cells, or corpuscles, encased in blood vessels, color the blood. Since there are about 35 trillion of these tiny, round, flat discs circulating in one's body at any one time, their sheer number necessarily lends their red color to the blood. Red blood cells are red only because they contain a protein pigment called hemoglobin (Heme – Iron, Globin- protein)which is bright red in color. Hemoglobin contains the element Iron, which has greater affinity for oxygen. Oxygen imparts a strong red color to the blood.