Kali’s dance...

 Shiva is white because he signifies the infinite divine light (prakasha), inert because the absence of movement and action reveals the consciousness pure, homogenous and compact.

On the other hand, Kali’s dance signifies the dynamic, active aspect of the Divine, and the dark color of her skin indicates that the processes of the creation are disolved in Kali.

Nonetheless, Kali performs her actions in the divine light and harmony, knowing that this is the best thing to do. Those who manage to pass all the tests and go through all the stages are in truth spiritual heroes, and they will be rewarded with Kali’s spiritual grace.

However, until God’s will does not manifest the creative impulse, the divine infinite energy (Shakti) lies potential, but unmanifested, inseparably united with Shiva, in his purely transcendent aspect.