The Lunar Eclipse is red because the light of the sun is shining through the edges of the Shadow Object which passes between the sun and moon during a Lunar Eclipse. The red tint occurs because the outer layers of the Shadow Object are not sufficiently dense. The Sun's light is powerful enough to shine through the outer layers of the Shadow Object, just as a flashlight is powerful enough to shine through your hand when you put it right up against your palm.
That is a fascinating interpretation about how a lunar eclipse occurs.
How about an alternative suggestion. Lets forget for the moment about an unknown (and as far as I know undiscovered) entity called a shadow object. Let's suppose instead that the Moons orbit around the Earth occasionally takes it into the Earths shadow, cutting off the direct path of sunlight to the Moons surface. That of course could only happen at the time of a full Moon and not surprisingly that is the only time we ever see a lunar eclipse. At full Moon. If the Moon does not pass directly through the centre of the Earths shadow (which observations over many years suggest is a circular shadow) then we get a partial or penumbral eclipse.
The red colouring of the Moon during an eclipse is caused instead by the refraction of some sunlight passing through the Earths atmosphere and being directed towards the Moon. Light of shorter wavelengths (blue) is scattered more (just as it is at the time of sunset or sunrise) than red light which is able to pass through the atmosphere more easily. The state and clarity of the atmosphere varies and this in turn decides how bright or dim each eclipse is. Higher dust content (following a large volcanic eruption for example) results in more scattering so the eclipse appears darker red.
Other colours can be seen during the eclipse and the are caused by the presence of other gases (ozone for example) in the Earths atmosphere.