Question: Why is Kali's tongue red in pictures?

Sri Chinmoy: Kali is showing her power aspect so that unaspiring humanity will not wallow in the pleasures of ignorance. On the physical, vital, and mental plane she shows her supreme power, for there is no other way for human ignorance to open to light. Her power itself is compassion, but also she has to inject fear. Otherwise, the ignorance of humanity will never come forward for illumination.