Hi! The metadata text applies to the labels that describe the action items. More of them show when you are viewing columns than when you are viewing using “fluid”.
Office in the selected row shows the Content: metadata text (Placeholder) combined with the Content: metadata text (Hovered) because my cursor was over it.
Yesterday shows the Content: metadata text (Overdue: Normal) state as 11:00PM shows the Content: metadata text (Due Soon: Normal). To see Content: metadata text (Due Soon: Placeholder), go to where you’ve set the date and delete what is in there. While you are editing, the placeholder color shows.
In the default Color Palettes, we don’t use different colors for every setting. This is partly because it is a bit jarring if the colors are too different as you edit, but we did want to provide the ability to set them for those who wish to customize. Those using your custom style will see them or not depending on the preferences they use for the view settings in Layout Preferences.
Strong shows up when you check “Show folders in the Outline” and it controls the text based on the status of the project or for the normal “Strong text color” that is what is used for folders. Also, when you are editing the text itself, the “Strong” color for the status applied is used. Try this with projects, action groups, and action items to see how it impacts the color. That question was so tricky I had to experiment and ask around, so thank you for a great question.
I hope this helps!