You Collection, Middle Volume. Radical: Red (chì). Cheng. 16 strokes. Page 1214, Entry 15.
Pronounced cheng.
According to the Explaining Graphs and Analyzing Characters (Shuowen Jiezi), it is sometimes written as a variant form derived from zhen.
According to the Erya, a work on terms (Erya, Shiqi), dyeing something a second time is called cheng. Annotation: Cheng means to dye red.
Book of Odes (Shijing), Zhou Nan section: The bream fish has a red tail. Commentary: Cheng means red. When a fish is exhausted, its tail turns red. Explanation of Characters (Shiwen): Cheng is written as the aforementioned variant in the Explaining Graphs and Analyzing Characters.
Also, according to the Collected Rhymes (Jiyun), it is used interchangeably with cheng.
Zuo Tradition (Zuo Zhuan), sixteenth year of Duke Ai: Like a fish with a red tail. Annotation: Cheng means red color. It is commonly written as cheng.