Question

why do viens appear blue in colour when they carry blood which is red in colour​

Answer 1

Answer:

Blood is always red, actually. Veins look blue because light has to penetrate the skin to illuminate them, blue and red light (being of different wavelengths) penetrate with different degrees of success. The oxygen-rich blood is then pumped out to your body through your arteries. It's bright red at this point

Answer 2

Explanation:

Blood is always red, actually. Veins look blue because light has to penetrate the skin to illuminate them, blue and red light (being of different wavelengths) penetrate with different degrees of success. ... The oxygen-rich blood is then pumped out to your body through your arteries. It's bright red at this point.