Created attachment 160774 [details] inverted representation compared to the pixel data When you see C=0 M=0 Y=0 K=0 it will be represented as white even though it has no selection of no channel. this inverts selection expectation because when C=1 on the cyan channel it will become black with selection. by consequence the map of Key will look like a normal grayscale version of the map even though it is selecting black not white. STEPS TO REPRODUCE 1. open a image in CMYK color model 2. verify the amount of any pixel compared to the specific solor selector and the amounts are inverted OBSERVED RESULT Alot of cyan will be rendered as black instead of white EXPECTED RESULT The visual representation of all maps following the same rule. white -> selected = 1 or 255 black -> selected = 0 SOFTWARE/OS VERSIONS Windows: 10 Qt Version: 5.12
I can confirm, it also affects the seperate image dialog, and it seems to be caused by the 'subtractive blending for CMYK', when setting that to 'additive', it starts to work as expected. Dmitry's already assigned himself, it seems.
Remove triaged keyword from CONFIRMED bugs