I work on Windows myself but all my course participants are on Mac and none of us could figure it out. It’s a simple right click on the colour bar on windows, just like the help suggests, but no combination of clicks and keys opens the same menus on the Mac books. Is there a button we’re not seeing? Something extra we have to activate? Or is the only option to add/remove sliders in the cpd files?
If they’re being unresponsive, I’ve found that sometimes just resizing the ‘Colour Manipulation’ window slightly forces the UI to refresh and makes them ‘grabbable’ again. Also, if you can’t get the sliders to move precisely, you can usually double-click the value in the table next to the slider and type it in manually as a workaround.