Answer & Explanation:
Object are usually considered opaque (its neither transparent or translucent) unless stated otherwise and the color of an opaque object is determine by the color of the light its reflects.
White light comprises of seven constituent of color: red, orange, yellow, green, blue, indigo, violet.
When white light is shown on a red object, it reflects red color only and absorbs all the remaining six colors. Hence, it appears red to the human eye.
