ANATOMY

Detailed explanation-1: -The colour blood red is a dark shade of the colour red meant to resemble the colour of human blood (which is composed of oxygenated red erythrocytes, white leukocytes, and yellow blood plasma). It is the iron in hemoglobin specifically that gives blood its red colour.

Detailed explanation-2: -RBCs contain hemoglobin (say: HEE-muh-glow-bin), a protein that carries oxygen. Blood gets its bright red color when hemoglobin picks up oxygen in the lungs. As the blood travels through the body, the hemoglobin releases oxygen to the different body parts.

Detailed explanation-3: -It’s red because of the red blood cells (hemoglobin). Blood does change color somewhat as oxygen is absorbed and replenished. But it doesn’t change from red to blue. It changes from red to dark red.