What are they?

Using common Western color symbolism, I’d assign each sin and its opposing virtue a contrasting color:

Sin	Color	Counterpart virtue	Color
Pride	Violet `#7B2CBF`	Humility	Soft gray `#A7A9AC`
Greed	Gold `#D4A017`	Generosity	Emerald green `#2E8B57`
Lust	Crimson `#DC143C`	Chastity / self-control	White `#F5F5F0`
Envy	Acid green `#7FFF00`	Kindness / gratitude	Rose pink `#E8899D`
Gluttony	Orange `#E76F00`	Temperance	Cool blue `#4A90A4`
Wrath	Scarlet red `#B3001B`	Patience / forgiveness	Light blue `#87CEEB`
Sloth	Muted indigo `#48466D`	Diligence	Bright yellow `#F4C430`

The general logic is:

Hot, intense, metallic, or sickly colors represent consuming impulses.
Cool, balanced, natural, or luminous colors represent their regulating virtues.

These associations are subjective, though—colors like violet, gold, and red can symbolize either vice or virtue depending on the culture and context.

I’d frame each pair as two expressions of the same primal fire—one consuming, the other guiding.

Sin Ember	Virtue Ember
The Crownfire Ember — Pride	The Bowed-Ash Ember — Humility
The Gilded-Grasp Ember — Greed	The Open-Hand Ember — Generosity
The Velvet-Flame Ember — Lust	The Ivory-Will Ember — Self-control
The Viridian-Mirror Ember — Envy	The Roseheart Ember — Kindness
The Evermaw Ember — Gluttony	The Measured-Flame Ember — Temperance
The Bloodstorm Ember — Wrath	The Still-Sky Ember — Patience
The Duskbound Ember — Sloth	The Dawnforged Ember — Diligence

Collectively, the sinful set could be called The Devouring Embers, while their counterparts could be The Guiding Embers.

Each pair could also be understood as one divided ember: This would be the ultimate goal for someone-- Ember Paradox

References