Black, the absence of color, is most often symbolic of death. It can also represent the darkness of sin and hate.
Black in Christianity
In Christianity, black is the liturgical color for Good Friday, which commemorates the death of Christ. Black can also represent sin, which results in death.
Black in Buddhism
In Buddhism, black signifies the primordial darkness. In the realm where it is dark, because there is no light reflected, there is also a sound which we cannot hear as it is so high on the scale of harmonics that it is inaccessible to the hearing capacity of any physical being. The wonders of creation may be manifested through the gradual slowing down of vibrations. The darkness becomes light, the shadows colors, the colors sound, and sound creates form.
One of the most interesting examples is represented by the so-called black paintings. The special genre of the black thangkas, the potent, highly mystical paintings portraying shimmering, brilliant forms appearing out of a translucent darkness, came to full fruition in the second half of the seventeenth century.
Their aesthetic power derives from the contrast of powerful lines against a black background, making them one of the most effective means to appreciate the Tibetan mastery of line work. There is a range of variations in the technique, beyond the boldness of gold lines over a black background, to large figures and settings and a variety of colors, and orange, flamed halos.
Black paintings, a relatively late appearance in Buddhist art, have added yet another means by which artists can conjure up visions of mysterious transcendent worlds. Like the fierce deities who are often the subject matter of these thangkas, the blackness signifies the darkness of hate and ignorance as well as the role these qualities have to play in the awakening of clarity and truth.
Thangkas with black background form a special category of contemplative paintings. They are a highly mystical and esoteric type, usually reserved for advanced practice. Black is the color of hate, transmuted by the alchemy of wisdom into compassion. Darkness represents the imminence of the absolute, the threshold of the experience. It is used for terrific ritual actions, the radical conquest of evil in all its forms - conquest not by annihilating, but by turning even evil into good. Thus, in the black paintings (Tibetan nagtang) the black ground casts forth deities in luminous visions of translucent colors.