The umbra casts the darkest shadow and represents the region in which all direct sunlight is obscured. The Moon enters total eclipse when passing through this region. Illumination of the lunar surface during totality is the result of sunlight refracted by Earth's atmospheric which casts a ruddy-copper glow. The penumbra represents the outermost region of Earth's shadow in which only a portion of sunlight is blocked by the Earth. However, refracted light still contributes a violet hue to the lunar spectrum.
Image is a composite of three frames.