'non-photochromic' is a modern English compound formed from the prefix 'non-' and 'photochromic'. 'non-' originates from Latin, specifically the word 'non', where 'non' meant 'not'. 'photochromic' originates from Greek elements: 'phōs/phōt-' (meaning 'light') and 'chrōma' (meaning 'color').

'photochromic' was formed in Modern English from New Latin/Greek roots ('phōt-' + 'chrōma') to describe substances that change color with light; 'non-photochromic' developed by adding the productive English negative prefix 'non-' to that adjective.

Initially the Greek roots referred separately to 'light' and 'color'; in Modern English 'photochromic' came to mean 'undergoing a color change in response to light', and 'non-' simply negates that property to mean 'not showing that behavior'.