青天

clear sky / blue sky / upright and honorable (official)

abbr. for 青海[Qing1 hai3], Qinghai Province

green / blue / black / youth / young (of people)

day / sky / heaven

Bao Qingtian, fictional nickname of Bao Zheng 包拯[Bao1 Zheng3] (999-1062), Northern Song official renowned for his honesty

popular nickname of Hai Rui 海瑞[Hai3 Rui4] (1514-1587), Ming politician, famous for honesty and integrity

green sea, blue sky (idiom); sea and sky merge in one shade / loneliness of faithful widow

(coll.) just and incorruptible official

in broad daylight / in the middle of the day / KMT emblem, a white sun on a blue background

thunder from a clear sky (idiom); a bolt from the blue

lit. thunderclap from a clear sky (idiom) / fig. a bolt from the blue