'unicolored-leafed' is a compound of 'unicolored' + '-leafed'. 'Unicolored' combines the prefix 'uni-' (from Latin 'unus', 'one') with 'colored' (from Latin 'color' via Old French), and the suffix '-leafed' is formed from Old English 'leaf' (lēaf) + adjectival '-ed' meaning 'having'.

'unicolored' developed from Latin elements ('uni-' + 'color') into Modern English 'unicolored'; 'leaf' comes from Old English 'lēaf' and produced adjectival forms like '-leafed' meaning 'having leaves of...'; these parts combined in Modern English to form the compound 'unicolored-leafed'.

Initially the parts independently meant 'one' (uni-), 'color' (colored), and 'leaf' (having leaves); together they evolved into the specific botanical adjective meaning 'having leaves of one uniform color'.