When direct categories are assigned to an image each one of those direct categories appears on the category bar.
However the assigned @keyword categories only appear once per parent category. I'm guessing this is by design to reduce the chances of the category bar becoming overly cluttered but thought I'd mention this in case it's not the intended behavior.
I noticed this after making the decision to use @keywords categories exclusively instead of direct categories.
Data-driven categories are special.
IMatch checks for unique colors. If all your @Keyword categories use the same color (or inherit from the parent), only one segment will be allocated in the category color bar in the file window. If you set individual colors for some of your keywords, the category bar will reflect these.
Ok, thanks Mario.
I have added a new paragraph to the color bar sub-section in the file window help topic so other users will know, too.