Shifting Beast Within is definitely a step in the right direction for righting the color pie imbalance currently tipping in Greens favor, so lets continue
These are typically green cards since green is the MTG color most associated with the power of nature, mana abundance, and lands
You win this round, Aaron Burrvalve.

The cards are: Serialized Poster Cards Andril, Flame of the West Aragorn, the Uniter Arwen, Mortal Queen Dawn of a New Age Gandalf the White Glamdring Hew the Entwood Last March of the Ents Mount Doom Palantr of Orthanc Radagast the Brown Saruman of Many Colors Sauron, the Dark Lord Shadow of the Enemy Spiteful Banditry Storm of Saruman The One Ring The Watcher in the Water Tom Bombadil Witch-king of Angmar Serialized Realms and Relics Cards The Party Tree Elessar, the Elfstone Bridge of Khazad-dm Argonath, Pillars of the Kings Three Rings for the Elven-Kings Morgul-Knife Herugrim, Sword of Rohan Ring of Barahir Shards of Narsil Balin's Tomb Barrow-Downs Isengard, Saruman's Fortress Minas Morgul Meduseld, Golden Hall of Edoras Paths of the Dead Weathertop Glittering Caves of Aglarond Green Dragon Inn Bag End White Tower of Ecthelion Osgiliath Fallen Capital Dol Amroth Redhorn Pass Bucklebury Ferry Inn of the Prancing Pony Henneth Annun Helm's Deep The Dead Marshes Valley of Gorgoroth Fangorn Forest Do LotR Special Edition Collector Boosters Have Cards from the Original Set

One mana for three cards is basically what cements this cards dominance