Holy Zohar text. Daily Zohar -207.

Tikkun 18 Continue

Ezekiel saw in his vision (Ezekiel 1) the image of a man with brightness around him like the appearance of the bow in the cloud, in the sky of rain. (Ezekiel 1:28). He fell on his face so he wouldn’t look at the bow.
Rabbi Elazar, the son of Rabbi Shimon, asked his father why it is forbidden to look at the rainbow, and Rabbi Shimon replied that 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 Kippah. It is called “Klipat Nogah,” and it has a 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.