"No makeup, face without any cosmetic" is "생얼"(saeng-ŏl) in Korean.
"Sang eol" is, compound word of "생 (Sang / raw)" and "얼굴 (Oel gul / face)".
The face without any makeup, refers to so-called, 민낯 (Minat), it refers to 맨 얼굴(Man oel gul).