面不改色

remain calm

面的英语翻译：

face; surface; cover; directly; range; scale; side
【医】 face; facies; facio-; prosopo-; surface

不的英语翻译：

nay; no; non-; nope; not; without
【医】 a-; non-; un-

改的英语翻译：

alter; change; correct; put right; rectify; revise; transform

色的英语翻译：

color; expression; hue; kind; quality; scene; woman's looks
【医】 chrom-; chromato-; chromo-; color