Created attachment 128408 [details] CMYK Channel Thumbnail vs main viewport 1. make CMYK image 2. Turn on only one channel. RESULT Main window with canvas display it correctly, but channels palette shows inverted thumbnail (unusual/incorrect for CMYK). See attachment. I expect thumbnail to be like what we see in main view /white for paper (no ink) and black for area with ink/
Note: this isn't a regression, it's always been this way. It's because CMYK actually is the opposite of RGB, so white is 0 and black is 255, not the other way around.
Git commit 3d7bb39c4612e8a0dc93ac76bcf2cdae4d206ae9 by Boudewijn Rempt. Committed on 20/05/2020 at 11:57. Pushed by rempt into branch 'krita/4.3'. Invert the channel thumbnail for CMYK M +10 -1 plugins/dockers/channeldocker/channelmodel.cpp https://invent.kde.org/graphics/krita/commit/3d7bb39c4612e8a0dc93ac76bcf2cdae4d206ae9
Git commit 915d4e613453be3c5214ed29db512bdc64e64a2b by Boudewijn Rempt. Committed on 20/05/2020 at 11:58. Pushed by rempt into branch 'master'. Invert the channel thumbnail for CMYK (cherry picked from commit 3d7bb39c4612e8a0dc93ac76bcf2cdae4d206ae9) M +10 -1 plugins/dockers/channeldocker/channelmodel.cpp https://invent.kde.org/graphics/krita/commit/915d4e613453be3c5214ed29db512bdc64e64a2b