Colors Dulling When Exporting from InDesign to EPUB

[John Paizs]

Hi. I made a graphic (e-)novel that I want to publish on AppleBooks and Kindle. In exporting from InDesign to Epub, something is happening to the colours. I've attached two screen captures. The 1st shows how the artwork appears in InDesign (which is also how it appears in the linked file in Photoshop; it's correct). The 2nd shows how it appears in EPub. You can see how the colors have dulled down. I've tried everything I can think of in InDesgn to fix the problem, but no luck. Can someone please help?

<Title renamed by MOD>

[James Gifford—NitroPress]

It is standard practice in most of the (largely) amateur EPUB world to hand-edit and -build EPUB files, and yes, you can do things like swap image files and edit code files. It is sometimes the only way to get a specific result, especially for non-compliant vendors or those who pursue absolute technical/standards-compliant files, especially*2 for those aiming for high levels of accessibility, which is the major focus in EPUB development these days.

It is not simple plug and play, though. Swapping files that are different from what the code expects, especially the very rigid, overwrought code of FXL, may produce anything from an unreadable file to just 'not quite what I wanted' results. That's where tools like Sigil and Calibre come in, allowing something of a managed approach to file editing and modification. Overall, it's as antiquated as running lead type on a Linotype, and generally not for the faint of heart.

You might explore to see what other graphic novel creators are using to get to a successful, compliant EPUB result. Or, they may just not be noticing, or care about, the color shifts... what the amateur book building crowd accepts can be... startling. 🙂

[John Paizs]

I hear you. Other graphic e-novel creators may just not be noticing the cololur shift. I actually only realized it by accident, just ther other day. But asking other creators how they're doing it is a terrific idea! That might be the perferct place to start. I can get on a forum of comix creators and see where that leads me. That's what I'll do! Thank you!!!

[Laura Brady · Accepted solution]

You don't need to zip and unzip if you are using a tool like Sigil. (You can also get a 30-day trial of oXygen XML editor which will let you open the file without unzipping. You will have to pay attention to the names to make sure they are exactly the same — case counts as well — and then replace the images in the images folder inside the EPUB. 

[John Paizs]

Thank you, Laura! Those are terrific suggestions. And I'm making them my Plan B. For a newbie like me the learning curve involved with those tools is daunting. I'm going to reach out to other e-comic creators first and see what they're doing re EPUBs. And I'll take it from there.... Thank you!!!

[James Gifford—NitroPress]

Well, to confuse what seemed to be a straightforward solution — I did a few tests with RGB images (copped from stock image sources, to make sure they were reasonably 'pure') and ran them through FXL export in v20.1/Win11. I then extracted the images from the resulting files.

Even with considerable compression, I see no significant color shift in any of them. That is, the original images, the images as displayed in Thorium, Calibre and Kindle Previewer, and the images compared side by side in a gallery app, show the same color balance, allowing some tiny bit for exact values. Noticeable shift in any of them. I then converted one image to CMYK  —with notable dulling — and ran the export again; the colors shifted, but to the brighter.

@John Paizs , I have to conclude it's something in your workflow, files or system setup, and it still looks an awful lot like a CMYK-RGB shift to me. The hitch has to lie in your processes and settings for your page-image files. You might try taking some clean/known/vanilla RGB images from another source and running them through FXL export to see if you're still getting a color shift in readers (and in the exported image file). 'Cuz right now, I can't find fault with ID's process, not when the steps are carefully managed.

[John Paizs]

Wow, jeez... OK, I downloaded two RGB stock images of colour bars, and took a random RGB pic from my photo library, and created a new InDesign document. In the new document window I clicked on the Web menu, and created a three page document in letter size. Then I placed my three RGB images, one per page, and exported to EPUB, selecting PNG. I opened the EPUB in BOOKS, made screen caps of the images. Then I used Sigil (yes, I downloaded Sigil! They have a Mac version!) to extract the three PNGS from the EPUB. And unfortunately again there was a dulling down of the exports. The screen caps have the same RGB values as the PNGs I extracted from the EPUB, plus or minus a negligable amount. So if the problem is in my workflow, I can't see where. Unless there's some CMYK setting in InDesign that I'm not aware of, because I agree, it's like I'm getting CMYK values in my exports. I wonder... could it be because I'm on a Mac, and this is some unknown problem with the Mac version of InDesign?? (BTW... I really appreciate you sticking witth this. That's really awesome... thank you!!!)

[m_0752]

Go to Links panel, click on image. See if it says RGB or CMYK.

If CMYK, try Edit>Transparency blend space... if needed switch from CMYK to RGB.
Excuse me if you've tried this, I'm skimming the discussion.

[John Paizs]

Thank you very much for these suggestions. In the Links Panel I clicked on my first image and under Link Info it says Format: PNG and Color Space RGB. And then it goes on to display the ICC Profile of the linked image, which is sRGB (etc). So yes, all looks how it should be there. In the Transparency Blend Space, under Edit,  "Document RBG" is selected, so all appears good there as well. But thank you so much again. The mystery lingers on...

[m_0752]

I'm quite new but have been working intensely.
I added a flat PSD for my cover as I understand the cover needs to be rasterized.
I didn't like the way the title looked in the export and relinked to a PSD with a live type title above the image layer.
Then the image color looked better in the export (why/how?)!

Have you published Print Replica on Amazon before? 
Do you know, will buttons made in ID be supported in Print Replica or any of the other platforms that allow fixed layout?

Thanks.

[James Gifford—NitroPress]

I'm not clear on your workflow here, but a file intended for EPUB export should NOT have a cover included as any part of the content. The correct way to include a cover is at the time of export, in which you should specify a file name to be processed and included in the EPUB as a separate element. (It's also good practice to keep the cover file modest in size; there is a persistent tendency for author/publishers to include massive resolution, print-ready files as the cover, which is just one more place for things to go wrong and for the export file size to become bloated.)

I strongly recommend NOT including a cover design as the first page and using the "Rasterize first page" option; that's a workaday solution for things like reports and journals, where it makes sense to just image the first page as a cover. Putting a designed cover in the file and then using Rasterize First is... poor practice and redundant as well.

Interactive features are almost entirely dependent on the reader used, and simply don't work well in most. I recommend against using them in any e-book unless you can control the reader the user will view it with.

[John Paizs]

Interesting about the colour shift on your cover when you relinked to a PSD file. But my project is my first graphic e-novel and I'm naviagting all this for the first time, so I'm encountering mysteries of my own in my exports to EPUB. I hope soon to understand what's going on with my exports but I don't yet.

I have not heard of Print Replica, so unfortunately I can't help regarding how it relates to InDesign. I'm sorry about that.

[James Gifford—NitroPress]

KDP is a poorly documented mish-mash of formats, subformats, tools, processes, guideines and results. I long ago gave up trying to sort out the alternate formats that are largely poor implementations of fixed-page layout... most of which will not display on Kindle readers anyway. (With few exceptions, the fixed-page options for children's books and "print replica" and so forth display only on mobile and desktop readers.)

Kindle is our best option for professional e-book publishing and sales/fulfillment, but only for reflowable books that meet some meticulous and somewhat arbitrary guidelines. KDP as a support and technical service is... a useless mess.

[John Paizs]

Good morning, James.... I have a BIG ask, and I'll understand perfectly if you feel it goes too far beyond the bounds of this forum... but how would you feel if I sent you the first 10 pages of my graphic novel, sans the text so I won't need to include the font. Then if you would export it to EPUB, and tell me what the result is. Is this something you'd be open to?

[James Gifford—NitroPress · Accepted solution]

Always happy to help within some reasonable limits. Fonts are a non-issue but if you send a file that has color shifts for you (send a link via DM), I can see if it behaves or HOW it behaves for me.

[John Paizs]

Wonderul. Thank you! I'll prepare the folder this morning and DM you the link after lunch. And what the heck, I'll include the font as well, then. Thank you!

[Nagy Peter]

Apparently the EPUB exporting routine does not honor the system display profile in InDesign. If you have an ordinary display (with a color gamut almost like sRGB) you will see no or minimal color shift. If you have a wide gamut screen with its on profile in the system (or a calibrated screen with a custom-made profile which is created during profiling) you will see a larger color shift. Basically the better display you have, the worse your EPUB will be... 🙂  The solution is to set the display profile to sRGB before exporting the EPUB.

[John Paizs]

Hi. Thank you so much for your reply. OK, I switched my display color profile from the default "iMac" to "sRGB IEC61966-2.1" (there is no simple "sRGB" option) and exported my grapchic novel to a fixed layout EPUB, and checked the colors ... and it worked! They are exact. The RGB values are EXACTLY the same as in the original TIFFs. Amazing!!!

I have already uploaded my graphic novel to Apple Books after I swapped all the PNGs in the EPUB using Sigil, but now for future updates I won't have to do that. Thank you for your help!!! Phew, what a relief to know there's a simple fix for this problem on my Mac!! 🙂

While I have you, though, there's something else that I found that InDesign was getting "wrong" in the fixed layout EPUB export of my graphic novel. I expanded the tracking on my titles as well as in the front matter text in InDesign, and centered it all. But in the EPUB fixed layout export, the tracking was no longer acurate (as widely spaced), and the text was no longer perfectly centered. I found however that if I converted the text in question to outlines in InDesign, that fixed it. So yeah, something else that I figure shouldn't be happening in my exports to fixed layout EPUB on my Mac.

But thank you so much again! This is a game saver!!!