And what colors does a black mage enjoy punishing most? Why, its enemy colors on the color wheel: green and white.
That's why Burden of Greed's artist Vance Kovacs was directed to picture a very particular artifact in the illustration. The piece depicts a druid on a dark day in the Tangle Forest, with a Talisman of Unity, the green-white talisman, hovering above him with lines of cursed energy being brought down on his head.
Aren't sure it's actually that particular Talisman? Check the diagram below, and compare the look of Talisman of Unity to the other talismans (of Talisman of Dominance, Talisman of Impulse, Talisman of Indulgence, and Talisman of Progress).