NOt so sure, but found:
What's a mandala ?
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Mandala comes from the Sanskrit word which means circle. Sacred
work, the mandala thrusts its roots deep into the religions like
Tantrism and Buddhism. Some wonderful examples can be notably seen
in Tibet.
At first sight, the mandala, which represents the cosmos, is a
kaleidoscope of geometric designs executed in vivid colors. A
closer look reveals a multilayered world of meaning.
For instance, the basic shape of a mandala is a
square, representing palacewalls with four gates
corresponding with the compass points. In the center is a circle in
which the sacred figure (or figures) that are the subject of the
painting may be depicted.
The center is often blue, a color signifying ignorance, a quality
which when transcended becomes wisdom. The four quadrants of the
square also have special meanings.
In many mandalas, east is white, which means anger or, transcended,
insight; south is yellow, which means pride or, transcended,
equanimity; west is red, which means greed or, transcended,
compassion; north is green, which means jealousy or, transcended,
achievement. Circles of lotus leaves surrounding the center and the
square signify purity, as does an outer rim of five-flamed fire.
The mandalas, which originally often were painted as murals, are
mainly used as a means to meditation.
http://www.artistenomade.com/gb/art_asie.htm
first, in front of the Buddha's image, use some clean soil to
construct a square mandala, the size according to one's wish. On
top of the mandala one should spread different kinds of grass,
flowers and burn different kinds of quality incense. Then kneeling
down with the right knee on the floor, mindfully reciting the
Buddha's name and with the hands in the Mudrani symbol, (i.e. each hand
bending the forefinger and pressing it down with the thumb and
placing both palms together before the chest) in reverence,
one should recite this Dharani 108 times. The showers of flowers
would rain down from the clouds and would thus be universally made
as offerings to Buddhas as numerous as the grains of sand of
eighty-eight million Ganges Rivers. These Buddhas will
simultaneously praise, "Excellent! Rare indeed! A Buddha's true
disciple!" One will instantly attain Unobstructed Wisdom Samadhi
and the Great Bodhi Mind Adorned Samadhi. Thus is the way to uphold
this Dharani."
http://www.geocities.com/usnisa_vijaya/web/eng/content/37.htm