'ash-gray' is a compound of the English words 'ash' + 'gray'. 'ash' comes from Old English 'æsc' meaning 'ash tree' or 'ashes', and 'gray' comes from Old English 'græg' meaning 'gray'.

The components 'ash' and 'gray' have existed in English since Old English ('æsc' and 'græg'); over time they combined in Modern English to form the compound color name 'ash-gray' (also spelled 'ash-grey').

Originally referring to the color of actual ashes, the term has retained this basic meaning and is still used to describe a pale gray shade ('color of ashes').