A white rainbow composed of mist was spotted in northern Israel on Friday by Nadav Yisraeli, an ornithologist at the Society for the Protection of Nature,
As the name suggests, this is phenomenon is very similar to the colorful rainbow we normally see but is formed in fog rather than rain. Because of the very small size of the water droplets in the fog – less than 0.05 millimeters – the colors in such a rainbow are very weak and you can see mainly the color white, with a little red on the outside and a little blue on the inside.
In a normal rainbow, the water drops “break” the light into its colors, and each color is perceived at a slightly different angle. In a rainbow that appears in the fog, the water drops are small and close to each other so that the colors “mix” again and are perceived as white. This is also what happens normally in clouds which is why they are perceived as white.
Many people, upon seeing the rare phenomenon, were reminded of a section in the Zohar (section 1, 72b) that differentiates between a dark-colored rainbow and a light-uncolored rainbow. The Zohar writes that a rainbow in dark colors reminds us that God made a covenant in the time of Noah promising not to bring a flood to the world. A colored rainbow should awaken us to repentance, that the gods of God’s covenant in the days of Noah we were bound by the law of the 16th century.
But, according to the Zohar, a rainbow of bright colors or entirely white marks the imminent arrival of the Messiah. It is a reminder of the covenant of the Biblical patriarchs and God’s promise to return the people of Israel to the Land of Israel. When God does so, he will adorn the people of Israel with all the decorations of a bride.