Thanks to a variation in a gene that influences the development of their retinas, people like Antico can see colours invisible to most of us.
In the book that resulted from our classes, Asylum and Exile, I try to make the invisible visible and give colour and wit to the dire cliches.
This is modern, working-class city life: a world where skin colour is invisible for some (Tracey's best friend is mixed race and her sisters are white, but it is never discussed) and omni-present for others; a world of absent fathers and dominant mothers.
Creatures with multifaceted, compound eyes, who see a fourth primary colour that is invisible to humans, who eat with their proboscis but taste food with their feet, who use their antennae for feeling, smelling and hearing.
A few, such as the orange roughy and the 7cm-long deep shrimp, Acanthephyra purpurea, are bright scarlet a colour that is invisible in the lunar glow from other creatures' luminescent organs.
But in his hands the dashes of pure colour turned and twisted, trading invisible and unstable lines of force.
The other becomes visible in a contrasting colour to reveal a previously invisible three-character code, derived from a random-number generator.
This is when the dense, sound-deadening smog somehow absorbs the light from the invisible sun turning everything a surreal sepia colour," one Palangkaraya resident told the Guardian.
Up until that point I'd been my usual invisible self, assisted by a neutral lip colour, but after I succumbed to the luscious temptation of Ginger Fawn the day was transformed.
