Metadata - color label set.
The colors are just UI elements for the "Label" metadata field and the set assigns which "Labels" are which colors.
What would you assign to purple? 0-5 are the stars and that leaves just 6-9 available, one short of the number of labels.
Assign purple: anything at all that worked! e.g. Ctrl - 9 for example, it doesn't matter what the shortcut is, so long as there is one!!
Ado not understand your comment about "The colors are just UI elements for the "Label" metadata field and the set assigns which "Labels" are which colors"
I want to know if its possoble to assign the custom color label.
Custom just means the "Label" metadata field contains a label that isn't part of the currently-active Color Label Set.
To assign a custom label, you need to use the label field in the metadata panel - just type in whatever you want. The color will be white.
PS - workaround for a purple key: use AutoHotkey on Windows, or Mac OS, or the like...