'two-tone' originates from Modern English as a compound of 'two' (from Old English 'twā') and 'tone' (from Greek 'tonos' via Latin 'tonus' and Old French 'ton'), where 'two' meant 'two' and 'tonos' meant 'stretching, tone'.

'tone' developed from Greek 'tonos' to Latin 'tonus' and Old French 'ton' before entering Middle English as 'tone'. The compound 'two-tone' formed in Modern English by combining 'two' + 'tone' to describe paired tones or colors.

Initially the elements referred to the numeral 'two' and the idea of a 'tone' (pitch or hue); over time the compound came to be used especially for visual color combinations, meaning 'having two colors' in modern usage.