'thermochromatic' originates from Greek, specifically the elements 'thermo' and 'chroma', where 'thermo-' meant 'heat' and 'chroma' meant 'color'.

'thermochromatic' was formed in scientific/technical coinage by combining the Neo‑Greek/New Latin elements 'thermo-' + 'chroma' with the adjectival suffix '-atic' and entered Modern English usage to describe temperature-related color changes.

Initially it meant 'relating to heat and color' in a general compositional sense, but over time it evolved into the more specific meaning 'changing color with temperature'.