The rare effect is created by light refracting off ice crystals in clouds, rather than water particles close to Earth, creating a 'flying' rainbow. 

'Late in the afternoon of June 5, a giant piece of colorful cloud appeared over the sky in Shenzhou Peninsula, Wanning City of south China's Hainan Province. A child on a fishing ship had the luck to observe this spectacular phenomenon and captured by a local photographer. 

'When the sun went down, the colorful cloud dispersed gradually,' says Ye Xin, of China's People's Daily Online.