The present structure is so impressive because its generally light façade is set off by a scattering
of the original, darker-coloured stones across many parts of its surface. Old and new stones
have been joined to give a clear, meaningful indication that the past is always part of the
future and that wounds can heal.(Extract from the Frauenkirche website)

Further information about the restoration:

. http://www.newworldencyclopedia.org/entry/Dresden_Frauenkirche