From Codex: Angels of Death, p. 33

Successor Chapters

General Information:

The three Space Marine Chapters shown here and the Dark Angels Chapter comprised the original Dark Angels Legion before the second founding, as described elsewhere in this book. Collectively the four chapters are known as the Unforgiven. The Angels of Absolution, the Angels of Vengance, and the Angels of Redemption share the ancient secret of the Dark Angels and that Chapter's mission to reclaim it's honour and eradicate the terrible shame of their part in the history. The three Chapters follow the Dark Angels pattern of organisation closely and each has it's own Inner Circle. They all have formations which are similar to the Deathwing and Ravenwing companies although they are not named as such. The Chapters of the Unforgiven coordinate their activities in regard of their secret mission and it is not unknown for the Supreme Grand Masters of the four Chapters to hold summit meetings on the Rock. Indeed the various Grand Masters of the Unforgiven are frequent visitors to the Dark Angels fortress-monastery.

Angels of Absolution

This Chapter's heraldry forms a stark contrast to that of the Dark Angels. All of the Chapter's warriors wear bone-white armor and it's vehicles and equipment are painted in this scheme.

Angels of Vengance

This Chapter has retained the traditional black armor of the Dark Angels Legion. The First Company wears black terminator armor and the monkish robes of the Inner Circle are jet black.

Angels of Redemption

Amongst the Unforgiven the Angels of Redemption have a fearsome reputation for their courage and zeal to right the ancient wrongs of the Dark Angels. Nothing can dissuade the Chapter form it's mission to hunt down the Fallen.

Possibly Related:

From www.armageddon3.com

The Angels of Vigilance

(Should the Armageddon 3 site come down, I'll put up this section, until then, go here for it)