IIRC, 青 in Japanese also can refer to either blue or green, though they also have a dedicated word for green (緑) and that is the one that usually gets used... this can catch people unawares when translating though.
Green (녹색) uses 綠. There's also 초록 which is 草綠.
赤: https://hanja.dict.naver.com/#/entry/ccko/ad2ad1893b5c49f8ab...
黃: https://hanja.dict.naver.com/#/entry/ccko/17a2b69699474d5bb8...