How often do people use 자동차 instead if just 차?
In my experience it's 50/50
보라해요!!
보라색인 자동차 -> 보라색 자동차
보란 자동차 should be accepted
보란 is not a word.
보라 is a Sino-Korean word so it must be paired with 색 to be used as an adjective.
thanks