The article deals with the semantics of the terms ӱrӱŋ and maŋan denoting white colour in the Yakut language. The aim of the article is to study the development of the words. The research material is based on lexicographical sources and the text of the epic poem – Olonkho. The novelty of this work is the comparative analysis of the Yakut colour terms with the South Siberian and Manchu-Tungus languages and establishment of their relationships. Two words having different origin and nature reflect different stages of language development and its historical connections. The term ӱrӱŋ dates back to ancient Eastern Turkic languages and has a sacred nature associated with early beliefs. The lexeme has a fixed distribution and retains the semantic structure. The adjective ӱrӱŋ has a great word-formation and phraseological potential; it is a component of complex words, pair-words and phraseological units. As in the Old Turkic language, the word performs the function of a noun. In the text, it acts as a permanent epithet to the word kӱn ‘sun’. Compared to the word ӱrӱŋ the term maŋan is an innovation, borrowed from the Mongolian language in connection with horse-breeding culture. Another loanword chaɤān is rarely used. Not only the adjective, but also the verb manxaix was borrowed from Mongolian into Yakut. In the adjective there was a semantic shift; in the Yakut language the meaning ‘white’ is updated, and the meaning ‘with an asterisk on the forehead’ fades into the background. In combination with other adjectives and nouns, the word maŋan forms compound color names that express different shades of white, as well as its saturation and brightness. The word maŋan has considerably expanded the area of use, replacing in some cases the function of the adjective ӱrӱŋ. In the epic text, the word serves as a permanent epithet of the word xallaan ‘heaven’. The word maŋan connects the Yakut language not only with the Mongolian and Manchu- Tungus languages, but also with the South Siberian languages, Khakass and Tuvan. In the system of colour terms, the word maŋan can be one of the common elements of the Siberian languages.