I feel to add that the solar plexus must balance out the root charka as it is where energy from the root is stored and transmuted to where it can be used by other chakras. Also red and yellow represent each chakra.

The inspiration for this was the tool lyrics for lateralus "black and white, is all I see, in my in my infancy, red and yellow then came to be, reaching out to me, lets me see"

Black and white, yin and yang, the polarities that make creation possible. Then red and yellow, sexual generative energy, and radiant useful energy. The rainbow continues to grow outward from there like a spiral. The song lateralus is cleverly done in a swing on the fibonacci spiral.

over the time i have realized t hat using the chakras for their true purpose needs strict chakra balancing .
chakra balancing is a real hard work which needs long time .
if the chakras are not balanced the information they will pass on to you will not be correct.
many people want to open their third eye but third eye open with heart ,throat chakra not aligned and balanced will give adverse affects.

Correct me if I'm wrong, but I think Om is the Mantra for Agya Chakra(6th Chakra). The order is as this:

Lam     -     Mooladhar Chakra(I, Base of the Spine)
Vam     -    Svadhistana Chakra(II, Genital)
Ham     -    Manipur Chakra(III, Navel)
Yam     -    Anhat Chakra(IV, Heart)
Ram     -    Visuddha Chakra(V, Throat)
Om      -    Agya Chakra(VI, Between the Eyebrows)
Aum     -    Sahasrara Chakra(VII, Top of the Head)

Actually, any mantra can be used to activate the whole Chakras, because the Chakras are like the neddles of a clock, so when one turns it would also make the other turn. Of course, for instance, the spiritual abilties of Sahasrara would have to wait 'till the 7th turn if we're using the Lam Mantra. If someone wants to directly achieve the abilities of Sahasrara Chakra, he/she would use the Aum Mantra.

Just look at the greys. They have really developed third eyes and not much else, and they've lost all their emotions and their ability to reproduce by getting external technology to do everything for them.

There's a mistake in my previous post. The Mantra for Manipur Chakra is Ram, while the Mantra for Visuddha Chakra is Ham.