secondary rainbow
The fainter, outer rainbow with reversed colors, formed by double reflection inside water droplets. Technical term in meteorology and optics.
A faint secondary rainbow was visible outside the primary rainbow.
The secondary rainbow has its colors in reverse order compared to the primary rainbow.
Standard kanji spelling for the secondary rainbow.
Compound of 副 (ふく, 'secondary, auxiliary') and 虹 (にじ, 'rainbow'). The reading ふくこう is a less common on'yomi variant.