Answer to Question #58861 in Optics for hamid

Question

why our fingers appeared red when we put it on a torch(mobile torch etc)

Answer 1

When you flash a torch through your skin, you see through the transparent skin into what's inside – the color of your blood. The blood that is flowing through the blood vessels in your fingers is red.
Also, the Like you already suspected, the absorption of blue light in tissue is higher than the absorption for red light.