Croma could be seen as something tangible with no further definition tan a possible ‘artist’s book’, or more specifically, a visual essay on human colour perception from a pictorial outlook. The painting Croma is the origin of the idea and it is reproduced in the first place on an independent piece that opens up, like the pages of a book. It also transits between the succession of visual experiences, actions and processes of experimentations gathered in another volume. A series of notes as a field notebook are gathered at the end. The idea is completed with a simple sensorial experience through two external elements: a red filter inserted between the pages extracts the experience, and a thin cotton veil protects it.