Yeah, when this was last on HN I looked into it and apparently 青 historically meant any cool or pale color. The article mentions set phrases where it referred t

Yeah, when this was last on HN I looked into it and apparently 青 historically meant any cool or pale color. The article mentions set phrases where it referred to green, but there are others that don't - 青ざめる (to turn pale), 真っ青 (pallid), etc. Interestingly, 青 historically applied to such a wide range of cool colors that it survives in contradictory ways - e.g. 青毛 (blue+hair) refers to a black horse, while 青馬 (blue+horse) usually means a white horse.