'dichroic' originates from Neo-Latin, specifically the word 'dichroicus', where 'di-' meant 'two' and 'chroa/chroma' meant 'color'.

'dichroic' changed from Neo-Latin word 'dichroicus', which itself was formed from Greek elements (compare Greek 'dikhroos' / διχρός meaning 'two-colored'), and was adopted into modern scientific English usage.

Initially, it meant 'two-colored', but over time it evolved into the current technical sense of 'showing or producing different colors depending on angle, polarization, or wavelength (especially in optics)'.