Write poems about rainbows

Problem description:

"Who put the blue and red lines together with the waist of clouds and rain? The Jade Emperor went out last night, and Wan Li set up a colorful bridge. " This is a poem about rainbows, so does he sing rainbows during the day (which often appears) or at night (which sometimes appears)?

Extra reward.

Analysis:

From "Night Sailing Ship" [Ming] Zhang Dai

This is the rainbow at night.

Rainbow is formed by sunlight being refracted and decomposed by raindrops in the air like a prism, so rainbow usually appears in sunny days. Surprisingly, however, rainbows will also appear in the night sky, but not during the day, but in the moon rainbow! Also known as "black rainbow"

Just like the sun rainbow in the daytime, the formation of the moon rainbow also needs a light source. Although there is no sun at night, if there is bright moonlight and appropriate clouds and raindrops in the atmosphere, a moon rainbow can be formed. The moon reflects sunlight, so the moonlight is also composed of seven visible monochromatic lights: red, orange, yellow, green, cyan, blue and purple, which reflects that the moon rainbow is also colored. But moonlight is much weaker than sunlight, so the moon rainbow is not as bright as the sun rainbow.