Deoxygenated blood is really a darker shade of red; This really is present in veins, and can be seen in the course of blood donation and when venous blood samples are taken. It is because the spectrum of light absorbed by hemoglobin differs between the oxygenated and deoxygenated states.[35] https://keegantczfk.tribunablog.com/5-essential-elements-for-blood-castle-mu-online-50680315