Bias thumbnails in a variety of colors?

[Tailspin45]

Pretty Christmas tree light thumbnail colors, but these bias frames from an ASI533MC are actually monochrome.

I restarted Finder and trashed the cache using Terminal, but they still are incorrectly depicted as colorful frames.

Fix?

[Sander Berents]

What a nice colorful set of thumbnails 

Right now the quick look plugin debayers the images if it detects a bayer pattern in the header, regardless the image type. It would indeed be better to not do that for calibration images. I'll change that.

Please share a few of these colorful bias images so I can investigate why each of them is depicted with such a different color?

[Tailspin45]

Sorry for slow reply. Forgot to set alert.

Colorful thumbs happens to Light subs, too. JPEGs and TIFs.

When I get Google to cooperate I send a link to some of the FITS files

[Sander Berents]

Observatory's QuickLook plugin isn't used for JPEGs and TIFFs. It is only used for FITS, XISF and SBIG images.

When you get it to work, please share a few of your images with Google Drive, or using iCloud.

[Tailspin45]

I know the QuickLook extension isn't for JPEGs and TIFFs, but they nevertheless have colored thumbnails.  I attached those screengrabs because I can't attach FITs files here, as you know.

Dropbox has three FITs files that have colored thumbnails but otherwisse seem completely normal.

[Sander Berents]

These three look normal to me in Quick Look, the same as when they are debayered in Observatory. This is on an 2013 15" Intel MacBook Pro with macOS Big Sur. How do they look to you?

[Tailspin45]

FITS files still have colorful icons, but only the small size. Large icons in lists are all a reasonable representation of the image.

This seems weird, but doesn't hurt anything so let's consider this resolved.