in Design
One colour doing all the work
A cover built around a single colour can be louder than one that uses all of them, provided the colour is chosen for the right reasons.
Plenty of memorable covers rely on one colour: a single saturated field behind a title, a monochrome photograph with one element picked out, a two-colour design on a coloured stock. Limiting the palette is a constraint, and constraints tend to force clearer decisions.
Why one colour can outperform many
Colour is often the first thing a reader registers about a cover, before the title and before the image. A cover built on one dominant colour gives the eye a single, immediate signal. On a crowded shelf or a page of search results, a flat area of strong colour can stand out more than a busy full-colour illustration, precisely because it is simple.
A single colour also carries mood with unusual clarity. A deep red, a pale blue, a sharp yellow or an almost-black green each make an impression that a multicoloured cover dilutes.
It helps with recognition, too. Readers often remember a book as the orange one long after they have forgotten the title, and a colour used consistently across a series makes the books look as though they belong together.
Choosing the colour
The colour should come from the book: its tone, its setting, its subject. Genre conventions matter as well, since some colours are strongly associated with particular kinds of book. Using the expected colour can reassure readers; using an unexpected one can make a book stand out, though it can also mislead.
It is worth looking at the competition before committing. If many recent books in the category use the same shade, a single-colour cover in that shade will disappear among them.
Getting it to print
Single-colour covers are demanding in production. A large flat area shows every flaw: uneven ink, banding, marks from handling. It also makes colour accuracy more noticeable, because there is nothing else to distract from it.
Screens display colour in RGB, and printing presses reproduce it with CMYK inks, which cover a smaller range. Some vivid colours, particularly bright oranges, greens and blues, cannot be matched exactly in CMYK, and a colour chosen on screen can print noticeably duller. It is better to choose the colour with that in mind, ideally from a printed swatch guide, than to discover the difference on a proof.
For offset printing, a spot colour, mixed as a specific ink rather than built from the four process inks, can give a more exact and consistent result. It adds cost, and it is not usually an option in print on demand, so it suits some projects and not others.
Finish affects colour too. Gloss lamination tends to deepen and saturate colour, while matte lamination softens it slightly. A proof on the actual stock with the actual finish is the only reliable way to judge the result.
Working within the limit
A one-colour cover still needs contrast. The title has to read against the colour, which usually means white, black, or a much lighter or darker tint of the same hue. Tints and shades of one colour can create a surprising amount of depth without breaking the idea.
The hardest part is resisting the urge to add. A second colour for the author's name, a small illustration in the corner, a gradient to make the field more interesting: each addition weakens the single idea the cover was built on.
One colour, chosen with care and printed well, can do more than a whole palette.