Sorry, I don’t know anything about color profiles, or how to create an image with one. I guess I could do that with Gimp?
Panorama 6 uses QuickDraw to draw images, so I guess QuickDraw doesn’t support this type of image. QuickDraw is 32 bit technology that is over 45 years old, and Apple hasn’t really been enhancing it at all for the past 5-10 years, so it wouldn’t be too surprising if didn’t get updated for something like a new color space model.
As far as I can recall, I’ve never heard of “Display P3” images. I don’t know what other color profile’s QuickDraw doesn’t support, or even what other color profile’s exist. Ok, just did a bit of Google searching, looks like P3 is a pretty new (~3 years) color space, so not surprising if QuickDraw doesn’t support it. I believe that this new color space is only of any use on the latest monitors like the 2016+ Macbook Pros and recent iMacs (ok, via Google found that the first Mac to include Display P3 support was the 2015 iMacz.z
Panorama X uses modern Cocoa APIs throughout, including for image display, so I suspect that the P3 profile will work with Panorama X. (If it doesn’t, it won’t work with most other Mac apps either.) Since Display P3 is so recent, it may be that it only works with fairly recent versions of macOS, I’m not sure. I see that at WWDC 2017 there was a session entitled “Get Started with Display P3”, so maybe it wasn’t supported until 10.13 High Sierra? Ok, I found another web site that says that at least some Display P3 support was added to 10.11 El Capitan.
What version of macOS are you using, Mark? It wouldn’t surprise me if QuickDraw never supported Display P3, but perhaps it was added later.z