It appeared in the title sequence of each episode and flashed a colour indicative of the episode's setting or tone; this would be accompanied by narration from the Time Voice.
By the summer of 1996, fans of the show would often wear pins of the Eye of Eternity and act as if they lived in the type of genre represented by the colour. This resembled Remote behaviour. (PROSE: The Book of the War)
The Red Eye of Eternity symbolised that the episode would show war or disaster through stock footage. The Green Eye symbolised ecological themes. In a reference to the "Cold" War, the Blue Eye symbolised that the episode would be a spy triller. The Black Eye represented black comedy.
Some colours only appeared once in the show's 78 episodes. The White Eye only appeared in an episode about a wedding, and the Brown Eye only appeared before the episode "Miss Hiroshima".