I and my colleagues have full access to our boss's inbox (Outlook), and he assigns email colour categories to each staff member. Recently he changed all the category names (from say "green" to "Hailey") and now the actual colour box in the navigation pane comes up blank. If I select an email itself I can see the (colourless)category as "Hailey" in the reading pane, but we need to be able to instantly see from his inbox nav pane which categories are green, blue, etc, rather than trolling through each individual email in his inbox.
Is there a way we can change it, or at least change it back?