Holy Zohar text. Daily Zohar -207.

Tikkun 18 Continue

Ezekiel saw in his vision (Ezekiel 1) the image of man with brightness around about him like the appearance of the bow that is in the cloud, in the sky of rain. (Ezekiel 1:28). He fell on his face so he won’t look at the bow.
Rabbi Elazar, the son of Rabbi Shimon asked his father the reason why it is forbidden to look at the rainbow and Rabbi Shimon replied that it is because the first three colors represent negativity in the correction process. We need to remove them to reveal the light in purity.
The three negative energies called Klipot (Klipah in singular), are “Stormy Wind”, “Great Cloud” and “Fire Flashing”. They come with brightness around them which is the fourth Klipah. It is called “Klipat Nogah” and it has dual identity. Its outer side is positive but the inner side is negative. It allows us to reveal its light and correct the other Klipot.
The top three colors (Red, Orange and Yellow) represent the three Klipot in the level of Chessed, Gevurah and Tiferet. When we look at the rainbow we connect to them with our eyes and draw these Klipot down to our level.

There is a special blessing to say when we see a rainbow
“בָּרוּךְ אַתָּה ה’ אֱלֹהֵינוּ מֶלֶךְ הָעוֹלָם, זוֹכֵר הַבְּרִית”.
“Baruch ata adonai eloheinu melech haolam, zocher habrit”
This blessing is actually a correction to the act of seeing the rainbow with the three Klipot. It connect s us to the moment after the flood (Genesis 9:12-17) when God promised not to destroy all living things on earth. It was a moment of mercy and this energy protects us from the negative Klipot.