Following the merciless deaths of “Horology,” our protagonist searches for a way to see and remembers about a color beyond human eyesight. They meet a (perhaps familiar) glassy-eyed man who tells them about the secret to see this color, tetrachromacy. The average human eye has three cone types in their retina, each one allowing someone to see different shades of color. Some animals such as sharks, zebra finches and caribou, however, have four different cones which allows them to see new colors that humans typically cannot experience, allowing them to spot things in their environments including ultraviolet light. The protagonist is fascinated by this and yearns to see “the fourth colour.” “Tetrachromacy” sets up a central idea on the album and is the beginning of the album’s final suite. Following the song’s release it would be occasionally referenced such as in “All Is Known” and “Dragon.”
“Tetrachromacy” was first made known as part of a Soundcloud leak on April 3rd, 2017. In the lineup was a track named “Tetrachromacy I.” While demos for the other Polygondwanaland tracks like “Polygondwanaland” and “Crumbling Castle” were saved, “Tetrachromacy” was one of three songs not documented. The studio version of the track was recorded by Casey Hartnett at Flightless HQ. The song saw an official release months later on November 17th as part of Polygondwanaland.
While the song had been a part of one of the band’s 2017 highlights, it did not see a live performance for a very long time. According to a response from the band before the premiere of the music video for “Dreams” the song was meant to be played in 2020 but was put to the side due to the shows being canceled. It wasn’t until 2022-05-26 at the Higher Ground Showcase Lounge in South Burlington that “Tetrachromacy” would be played, at least based on our knowledge of the band’s setlists. Like other songs from the album it had shed its acoustic skin and was played all electric. It was played one more time on 2022-10-14 at The Palace Theatre in St. Paul, this time at the beginning of the show, and then was never played again though it was printed on the setlist for 2022-11-02.