Evolution of human colour vision as 'visual purple' receptor proteins, are encoded by Rh1, OPN2 and RHO genes. They are characterized by extreme sensitivity to light and enable monochromatic human vision in low light or dim conditions. They are broken down into retinal and opsin when exposed to these conditions. Humans have 3 types of photopsin proteins found in the cone cells. Long Wavelength Sensitive Opsin (Red cone opsin) – Encoded by the OPN1LW gene with a λmax of 560 that is found in the yellow-green electromagnetic spectrum despite its name. Its sensitivity to the colour red is still known to be higher than the
Light and Colour (Goethe's Theory) – The Morning after the Deluge – Moses Writing the Book of Genesis painting is a reference to Goethe’s "Theory of Colour", which explains the colour yellow as being the first colour transmitted from light. The form of the painting is circular, symbolising the construction of the human eye, changing the focus of a typical linear splitting of space to a more subjective portrayal. The colour yellow is typically optimistic, but Turner captures the negativity of yellow by attaching the colour to a light that is subject to change. The morning sun aspect of the colour is something transient. "Light and Colour" was among three paintings stolen from a Frankfurt museum in 1994.