Evolution of human colour vision other two human opsins. Middle Wavelength Sensitive Opsin (Green-sensitive opsin) – Encoded by the OPN1MW gene with a λmax of 530 found in the green region of the electromagnetic spectrum. Short Wavelength Sensitive Opsin (Blue opsin) – Encoded by the OPN1SW gene with a λmax of 430 found in the blue region of the electromagnetic spectrum. Certain parts of opsin genes and the vision of various species, including humans, has been known to change over time with different environmental changes. Recent studies have shown that primitive nocturnal mammalian ancestors had dichromatic vision consisting of UV–sensitive and red–sensitive traits. A change
Trooping the Colour (and, once they have collected their colour during the ceremony, as 'Escort to the Colour'). At the outset, the colour is held by the Colour Party - a colour sergeant and two other guardsmen of No. 1 Guards, standing well-spaced on the northern side of Horse Guards Parade. Once obtained by the Regimental Sergeant Major of No. 1 Guard, the colour is borne through the ranks of Nos 2-6 Guards by an Ensign of No. 1 Guard. It is a great honour for a young officer to carry the colour in this ceremony, as historically only the most courageous Ensigns