Japanese has the cool feature that you can clearly identify siro/kuro/aka/ao (a fairly typical four-way white/black/red-yellow/blue-green distinction) as the mo

Japanese has the cool feature that you can clearly identify siro/kuro/aka/ao (a fairly typical four-way white/black/red-yellow/blue-green distinction) as the most basic colour words with relatively little diachronic analysis: they're the ones that stand alone in the rather limited class of 形容詞 ("i-adjective") stems. You can almost trace the development of colour terms through the vocabulary strata...