A Tibetan prayer flag is a colorful rectangular cloth, often found strung along trails and peaks high in the Himalayas. They are used to bless the surrounding countryside and for other purposes. Prayer flags are believed to have originated with Bon. In Bon, shamanistic Bonpo used primary-colored plain flags in Tibet.
 
The colours meaning
Blue represents the sky, white represents the air, red symbolizes fire, green symbolizes water, and yellow symbolizes earth. All five colours together signify balance. Monks gather in Tibet.