Holy Zohar text. Daily Zohar -330.

Tikkun 21-71

Just like the flame of the candle has different shades of color, so does the body. The light that is close to the wick is red like the liver, green as the spleen and black as the bile.
The light blue color does not exist in the Sitra Achra, which is the impure side and that brings fear on them because it is the color of the Holy Throne. Hence the common ‘blue eye’ that many cultures wear on themselves for protection.

The bile holds the soul level of Nefesh as a prisoner in the body. It influences the mood of a person and can bring him to depression.
The Zohar quotes this verse from Proverb 30:23 “תַּחַת שְׂנוּאָה, כִּי תִבָּעֵל; וְשִׁפְחָה, כִּי תִירַשׁ גְּבִרְתָּהּ” .
Its deeper meaning translates to “Bring the light to the wife (the heart) because the hated one (female, Bile, and the negativity in the blood system) could inherit her mistress”

The three parts that control the blood and circulate life in our body are the Liver, Spleen and Bile. Our soul is pushed into the body and is held in the blood until it stops circulating.

While we’re alive we connect to the environment through breathing (Air), drinking (Water) and eating (Earth) that are channeled through the blood (fire) to sustain the soul in the body.

The quality of the air and food will keep the soul circulating in good condition and the negative side can not control the body. We can then have better spiritual connection and elevate our soul with the heart and mind to the spiritual system that balances the fire in our body.
Another way to have elevation is with extreme fasting or water diet. This is a situation when we control the body and it ‘thickens’ the blood. It burns the negativity in the body when we stop the desires that connect us to the material world.