moonbow

Red, orange, yellow,green, blue, indigo and violet become a rainbow. A simple light split 7 colour. a round rainbow is meaning peace and harmony.
Nüwa 炼五色石补天，彩虹即五色石发出的彩光。In the Bible, it says God made a rainbow, after he flooded out evil from the world, a promise to never harm the Earth like that again.

Rainbow also had made by moon, that call moonbow or white rainbow. They are always in the opposite part of the sky from the moon. 月虹，顾名思义，即是在月光下出现的彩虹，由于是由月照所产生的虹，故通常只见于夜晚。且由于月照亮度较小的关系，月虹也通常较为朦胧，且通常出现于月亮反方向的天空。由于月虹的出现需各种天气因素的配合，所以是非常罕见的自然现象。月虹，又称晚虹，是一种非常罕见的现象，在月光强烈的晚上可能出现，由于人类视觉在晚间低光线的情况下难以分辨颜色，故此晚虹看起来好像是全白色。