From the publishers:
In some worlds, Magic may not be seen as a force in and of itself. In some philosophies, magic can not be classed by types of effect, like Evocation, Illusion or Abjuration. Instead, it might be seen as a result of fundamental aspects of arcane metaphysics.
One such theory holds that all magic is a result of the principles of Colour.
Green is the colour of Animals, Plants, Water and Air. But, unlike the powers of the Druid, the Colour Green concentrates on bending Nature to the will of the mage, rather than coexisting with it. If a Druid is a Nature Priest, a specialist in the Green is Nature Wizard.
Those that devote themselves to understanding the Green are able to manipulate the Environment, Command Animals and Plants to act as they will, and even to draw upon the characteristics of natural things to mimic or manipulate them.
The most focused of specialists of the Green might become Animists. An Animist is to nature what a Necromancer is to the dead. They believe there are spirits inhabiting all natural things, from plants and animals to the rivers and winds, but do not intrinsically think that these spirits are worthy of worship: but rather think that they are servitors and creatures to be commanded.
Included in this product:
3 new Clerical or Mystical domains
a linked reclassification of one twelfth of the spells of the players handbook, with some new spell effects to fit the spells into Chromatic Magic Theory
a whole new character class, the Animist. This spellcaster learns great power over the Green, with abilities akin to a sorcerer or specialist wizard combined with those of a druid.