I have tested (IM 6.4.1-9 Q16 Mac OSX Tiger)
convert <image> -format "%[channels]\n" info:
on several images. RGB, RGBA, CMYK, CMYKA report fine, but a grayscale image still reports as RGB.
This is not urgent as I can combine
convert <image> -format "%[channels]\n" info:
To distinguish gray from rgb, but at some point in the future it might be nice to have "%[channels]\n" report gray and graya directly.
Thanks for implementing this.
Fred