The focus of the paper is a detailed analysis of the functional-semantic meaning of colour epithets occuring in the basic corpus of O. Mandel'stam's poetry (330 poems). The author of the paper carried out analysis of the frequency of usage of colour epithets in different periods of the poet's creative work and summed up the results in a table showing their dynamics throughout Mandel'shnam's poetic corpus. In the course of the context-and-image analysis, stable semantic parallels between metaphorical meanings of colour epithets in various poems were revealed. The next step in the research was analysis of their symbolic implications in Mandel'shtam's poetic language and an attempt, with the help of the key thus obtained, to get a deeper insight into his lyric heritage as a whole. The research shows that colour epithets are not so numerous, they make a very small percentage of Mandelshtam's poetic vocabulary, but that is the reason why they acquire special symbolic meaning recurrently found in his lyrics.