When you set the ColorSpace to CMYK, you expect the channels to be "Cyan, Magenta, Yellow, Black".
However, it isn't being that way. I attached an screenshot, where channels can be clearly see as "Cyan , Green , Blue, Black".
Even when i set the ColorSpace to sRGB , the channels available are "Cyan, Green, Blue".
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On the screenshot above, i defined the ColorSpace as CMYK
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Version: MagickNET-Q16-x64 v7.0.5.501