Evolution of human colour vision similar. Tritanopes are missing the short wavelength sensitive opsins and see short wavelength colours in a green hue and dim compared to other colours. They may also see some short wavelength colours as black. Other perception problems include distinguishing yellow from pink or purple colours being perceived as shades of red. Researchers have found that trichromacy has advantages over dichromacy or anomalous trichromacy at further distances. This is believed to occur because visual cues such as shape decrease for colour vision as distance increases for targets of a smaller size. Using tests for spotting fruit pieces in bushes at distances
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