For Warbreaker, I was looking back a little further, shooting for a more Renaissance-era feel. And so, I extrapolated from the early beliefs that similarities created bonds. In other words, you could affect an object (in this case, bring an object to life) by creating a bond between it and yourself, letting it take on a semblance of your own life.
Moving beyond that was the idea of color as life. When a person dies, their color drains from them. The same happens when plants die. Vibrant color is a sign of life itself, and so I worked with this metaphor and the concept of Breath as life to develop the magic. In this case, I wanted magical powers that would work better ‘in’ society, meaning things that would enhance regular daily lives. Magical servants and soldiers, animated through arcane powers, worked better for this world than something more strictly fighting-based, like in Mistborn.