Nyaya – The crystal and the red flower called japa.

स्फटिकलौहित्यन्यायः

This maxim is used to denote the property of a purely transparent object to reflect the colour of a thing presented before it, just as a crystal which is naturally white, looks red, when a red flower called japa, is placed before it, and the flower being removed, the crystal assumes its own white colour again.