'greenish-blue' originates from the combination of the words 'green' and 'blue', where 'green' meant 'the color of grass' and 'blue' meant 'the color of the sky'.

'greenish-blue' evolved from the Old English words 'grēne' and 'blēo', eventually becoming the modern English term 'greenish-blue'.

Initially, it meant 'a color between green and blue', and this meaning has largely remained the same in modern usage.