Nour in Farsi means Light.
 In the story “The perfect art”, Mawlana Rumi (Persian poet and Sufi mystic who lived in the thirteenth century) speaks about a challenge between Chinese and Byzantine, launched to determine which of the two peoples was the best in the art of painting. In the home of the sultan, two rooms exactly alike and located opposite each other, were chosen to implement the challenge.
 The Chinese asked the Sultan 100 colors to accomplish their work, the Byzantines instead limited themselves to clean the walls from all rust and dirt, until it become crisp and clear as the sky.
Mawlana explains that in the art of painting there is the technique of ” the absence of color “: the colors can be compared to the clouds and their absence in the light of the sun and moon. Like the clouds, the colors are visible only through the light.
 When the Chinese had finished their work they were very satisfied, even the sultan was impressed by the paintings realized, but his surprise was even bigger when he could admire the work of the Byzantines. Thanks to the purity achieved by the walls, the wonders painted by the Chinese in the front hall, were reflected in the wall of the Byzantines, with a brilliance that exceeded the original paintings.
Rumi, Hear the music of the soul, Arnoldo Mondadori Editore, 2008 Milan.