GIMP-2.99 color changes when converting between linear and perceptual precision
This is with GIMP-2.99 updated through commit d7345a6a . I opened a file that was at 32-bit linear precision, and then changed the precision to "perceptual", at which point all the colors changed (as noted below, changing back to linear precision does recover the original colors).
I think this might not happen all the time, but I haven't yet managed to reliably trigger the circumstances under which the colors stay the same after changing between linear and perceptual precision.
Here's a screenshot of the original linear precision XCF file, showing a dark blue background and a green square:
Here's the actual XCF file, though it's before I added the second Sample Point shown in the screenshot:
Here's a screenshot of the above XCF file after doing "Image/Precision" and selecting "Perceptual gamma (sRGB)":
Here's the XCF file after it was converted to perceptual precision:
At least on my computer, converting this second XCF file from perceptual precision back to linear precision does recover the original colors.