What color is blood?

Blood inside your body is red according Madscience network, posted by Lillian Mundt a clinical laboratory science biology lady :) Since 40-45% of your blood is made up by red blood cells, a dominating factor our blood is red. Red blood cells are red because they have a protein called hemoglobin which contains iron. Iron loves to bind to oxygen. Oxygen + Iron equates to red. (didn't explain why) The more oxygen the redder the cell. Our viens appear blue because they do not recieve as much oxygen as our other organs. The vital organs take up most of the oxygen in the blood and as blood travels back to the heart and lungs it has less and less oxygen. Bottom line; Blood is RED!