I seem to have a lot more difficulty remembering color words than other vocabuary in Korean. Apart from just repating and repeating again, are there tricks or techniques for remembering them? I often confuse 빨간색/파란색 and 갈색/회색.
Etymology is frequently a good way of remembering words.
빨간색 is 빨갛- + -ㄴ + 색, where 빨갛다 is a tense form of 발갛다, which comes from 붉- + -어 + -하다, and 붉다 comes from 불(fire). Fire is red, so 붉다 and 빨갛다 are red.
파랗다 comes from 프르- + -어 + -하다, where 프르다 is an old form of 푸르다, which comes from 플 (modern form 풀 "grass"). Grass is green, so 푸르다 is green. Later the color shifted from green to blue, which makes 파랗다 mostly mean "blue".
갈색(褐色) and 회색(灰色) are Sino-Korean words. 회(灰) means "ash", and ash is grey.