When you practice Green Tara, this is how you should place the Om Ah Hung syllables
Visualize an upright white
Om syllable inside and to the
top of the head/brain
Visualize an upright red
Ah syllable inside the throat
Visualize an upright
Green Tam syllable at
The heart in the front of
The chest
Visualize an upright
blue Hum syllable at
the heart in front of the Tam syllable