The export says I have a color picture — what do I do?
The warning names a number of pictures and says this:
Printers price a color interior per page for the whole book, not per picture.
That is the whole reason the check exists. It is not about how the page looks — it is about which price band your book falls into. One picture with color in it on page 12 of a 300-page novel makes all 300 pages color pages, at every printer we know of. It is usually the single most expensive thing a black-and-white book can do by accident.
What to do about it
The warning carries a button: Set it in gray for print. Press it and the picture goes into your print PDF as a gray image, the whole book stays in the cheaper tier, and the warning becomes a note saying what was done.
Three things that button does not do, all deliberate:
- It does not touch your ebook. Color costs nothing in an EPUB, so your ebook keeps the picture exactly as you made it. Mono paperback, color ebook — which is how the trade has always worked.
- It does not touch your Word file. Nothing we do here ever writes to your manuscript.
- It does not happen on its own. Converting your artwork is your decision, so it waits for you to press something. If you never do, the warning stays and the file stays as you made it.
Changed your mind? The note it leaves behind carries Put the color back.
If you would rather fix the picture at the source — worth doing if you will use it again — re-save it as a genuine grayscale file: in Preview on a Mac, Tools → Adjust Color, drag Saturation to zero, then File → Export; in most editors, Image → Mode → Grayscale. Re-import your .docx and the warning never appears in the first place.
Why a picture you are sure is black and white gets named
Almost always because it is almost gray rather than gray.
A picture can look perfectly black-and-white and still carry pixels a single level off neutral — 6, 5, 5 instead of 6, 6, 6. Image editors and AI upscalers leave this behind routinely. You cannot see it. A printing press can, and their automated check is no more forgiving than ours.
The warning tells you which kind you have. If the color is faint it says so and gives you the number — "the furthest any pixel strays from neutral is 1 of 255" — because a picture that is one level off was rounded by software, and one that is 160 off is a photograph. Same warning, same button, very different decision.
There is a second, quieter reason a picture gets named. A file can be built as a grayscale image, or it can be an ordinary color image that happens to contain only gray pixels. We treat those differently, and we have to:
- A file that declares itself grayscale — a PNG saved in grayscale mode, or a single-channel JPEG — is taken at its word. Nothing is measured, because there is no color in the file to find.
- Any other file has its pixels read, one by one, and a single pixel with real color in it fails the test.
That second path runs through your browser's image decoder, and decoders are allowed to round. Saving the picture as a true grayscale file is what takes the decoder out of the decision entirely — which is why it is the fix we recommend rather than a workaround.
What if the picture is meant to be in color?
Then leave it, and know what it costs. Ask your printer for the color-interior price at your page count before you commit; on a novel it is usually several times the black-and-white price per copy, for the life of the book. Many authors who see the two numbers side by side decide one photograph was not worth it. Some decide it was. Both are reasonable; guessing is not.
If only a handful of pages need color, the usual answer in the trade is a plate section — a short signature of color pages bound in the middle — which some printers price separately. That is a conversation with your printer, not a setting here.
Should I try a different browser?
No — and if that ever appears to help, the picture still has color in it and the file you upload to the printer will still be a color interior. Use the button, or fix the picture. Not the messenger.