Color and contrast
Color is the fastest signal a cover sends. It arrives before shape, well before type, and long before anyone works out what the illustration is of. A reader scrolling a category page has formed an impression of your book from its palette alone, without deciding to.
That makes the palette worth choosing rather than inheriting from whatever your artwork happened to produce.
Value contrast is the one that decides legibility
Here is the distinction that fixes most unreadable covers.
Hue contrast is how different two colors are — red against green, blue against orange. Value contrast is how different their lightness is: how far apart they would sit in a black-and-white photograph.
Type legibility rests almost entirely on value. Red text on a green ground has enormous hue contrast and is close to unreadable, because the two sit at a similar lightness. The letter edges have nothing to push against, so they vibrate and blur.
This is why "I used complementary colors" is not an answer to "I cannot read the title." Complementary colors are opposite in hue. They are very often identical in value.
The grayscale test
Strip the color out of the whole cover and look at it cold.
If the title still leaps off its background, the contrast is real and will survive anything. If it sinks, you were leaning on hue — and hue is the first thing to go, at thumbnail size, in a black-and-white listing or printed catalog, on a dimmed phone in daylight.
While it is desaturated, check four things, not just the title:
- The title against the exact part of the art behind it, not the average of the image. A title crossing a light region and a dark one has two contrast problems, not one.
- The author name and any series line. Set smaller, they need more value separation than the title, not less. Gray on gray is where they quietly disappear.
- The spine against the front and the back — Designing a spine people can read on a shelf takes that further.
- The barcode area. The block is 2 × 1.2 inches and something gets printed into it. A white barcode panel dropped on a dark, busy back cover is a value collision, and gray shows it at once. See What goes on the back cover.
Run this alongside The thumbnail test. They catch different faults, and a cover that passes both is hard to make illegible.
Color blindness needs no separate test
The common forms confuse reds and greens, and they cost you a reader in exactly one situation: when hue alone separates your type from its ground — red on green, green on brown, orange on olive. To those readers each of those pairs is one tone.
You do not need a simulator. A cover that survives grayscale survives color blindness, because both ask the same question: is there enough difference in lightness? Legibility, and the readers you are leaving out covers the rest of that ground.
In the Cover Maker. Cover check renders your design at the size a store shows it and puts a grayscale panel beside it, so the small view and the desaturated view are one step rather than an export and a trip through an image editor. Start your cover → · about the Cover Maker
Limit the palette
Two or three colors. That is the whole rule, and most of the difference between designed and accidental.
A structure that works: one dominant color holding most of the cover, one secondary supporting it, and one accent used sparingly where you want the eye to land — often the title.
Covers that fail here rarely chose four colors. They accepted everything the artwork contained. AI-generated art is especially prone to it, arriving with a dozen colors and no hierarchy; regenerating with a stated scheme, or pulling the type colors back to the two dominant tones, is often the single change that makes a cover look professional — see AI cover art that does not look like AI cover art.
What the palette says about genre
Roughly, and with plenty of honorable exceptions:
| Palette | Reads as |
|---|---|
| Red, black, white | Thriller, danger, urgency |
| Teal and orange | Contemporary thriller, action |
| Bright saturated flats | Rom-com, cozy, upbeat contemporary |
| Dark jewel tones with metallics | Fantasy, romantasy |
| Muted earth tones | Literary, historical |
| Near-black with one accent | Horror, dark thriller |
| White with a single graphic | Literary, nonfiction, "serious" |
Pale, washed-out palettes have been on the way out; the direction is bolder, with strong color doing work that fussy detail used to. For what each shelf expects, see Color, and what each genre expects of it and Genre conventions: what your cover has to promise.
Paper is part of the color
Two things separate the cover you approve on screen from the one that arrives in a box.
Ink is darker than light, always in the same direction. Your screen emits light; paper only reflects it, and the range of colors ink can make is the smaller one. Anything outside it gets moved to the nearest color that fits, and saturated blues, electric greens and anything neon are the reliable casualties. The mechanism is in Why your cover prints darker than it looked; the part that belongs in a palette decision is this. Do not build a cover on a color that only exists on a backlit screen, and treat whatever lives in the deepest few percent of a dark image as lost.
The sheet is your lightest color. Large white or near-white areas come out as the color of the stock, which is not screen white. Cream interior paper does not change the cover, but it changes anything you carry inside — see White or cream paper? and Using color inside the pages.
If your cover is mostly one flat field, order a proof before committing. Flat areas show banding and shift far more than busy illustration does, and no screen shows you either; Proofing on screen or on paper sorts which faults belong to which.
Take the palette out of the artwork
The most reliable way to get a coherent wrap is to lift the palette from the art rather than choosing alongside it. A title in a color that appears somewhere in the image looks intentional; one in a color that appears nowhere in it looks stuck on.
That is what Match Front Cover does — it reads the dominant colors out of your front artwork and offers them as swatches for the spine and back, so the wrap holds together instead of the spine being a guess at the front.
Make your cover
The Cover Maker is free to use: name your book, bring your artwork, and it draws the full wrap — front, spine and back — to your printer's own measurements. You only pay when you want the files without the preview watermark.
Next: Typography and hierarchy · More: Why your cover prints darker than it looked · Composition and negative space · Alignment, spacing and why an amateur cover feels off