Update: This issue has been more or less resolved; it turns out that the images in question had CMYK color profiles attached rather than RGB color profiles, so Apple software was (possibly correctly) displaying them in a way that the designer hadn’t intended.
Leaving the post in place for historical purposes.
The other night, I discovered a completely weird Apple image-display bug: Apple Mail and Preview and Quick Look are displaying at least some images with noticeably reduced color saturation.
The designer who’s designing a book cover for me had sent me a JPG image as an email attachment. I looked at the image in the email that it was attached to, and I found it disappointingly washed-out-looking. I double-clicked the image (in the email), and it opened in Preview, and it still looked the same. So I assumed (without thinking about it) that that was how the designer intended the image to look. I spent a while sampling colors from it, and concluded that when expressed as HSV numbers, all the saturation values were about 30 percentage points lower than they should have been. Also, an area that should have been black (#000000) was instead gray (#292929).
But I went to check one last thing, and I happened to open the attached image file in GraphicConverter (an application that isn’t made by Apple)—
And the colors were correct. The color saturation was what it should have been, and the black was black.
I don’t know what application the designer used to create the image, nor what operating system they’re using. But it turns out that for at least the last three JPG images they’ve emailed me (and the last PDF, too, I think), the same thing is true. In Apple software (specifically in Apple Mail, in Preview, and in Quick Look in the Finder), the images are noticeably washed-out-looking. But if I open that same attachment image file in GraphicConverter or Photoshop, it looks the way it should.
I’m baffled—I’ve never seen anything like this before.
Kam and I came up with a few different theories about possible reasons for something like this to happen, but none of them turned out to be what was going on. (Among other things: it’s not a monitor-calibration issue, because the same problem occurs on two of my displays and on Kam’s computer. It’s not a True Tone or Night Shift issue; the same problem occurs with or without those features enabled. It’s not a macOS-accessibility-features issue; I tried all the accessibility features that looked relevant.)
(I’m using macOS Ventura 13.4 on a 2023 MacBook Air. The monitor color profile I’m using for the built-in display is Color LCD, which was the default for this computer; I haven’t changed it. I don’t have access to a Windows machine to try stuff there.)
After some further web-searching, I now suspect that the issue might have to do with an ICC profile embedded in each image. I don’t know enough about color profiles or embedding to be sure, and the minimal testing that Kam and I did last night (by trying to remove embedded color profiles) didn’t seem to support this idea, but it’s the only plausible-sounding idea I have left.
So: have any of you seen this kind of problem?
And for images that have this problem, do you know if there’s an easy way to get Apple software to display the images correctly?