Just added an IMAP email account, and suddenly all the colours of categories in my email folders have gone wrong, and will not allow me to reapply the correct colour catgory.  Then I realised Outlook has created a new sub-inbox within my 'Inbox' for the new email account, and a second one called 'On my computer'.  It's the Category colours in the original 'Inbox' that are wrong, in the sub-inboxes they are still correct.  I wonder why Outlook has done this.  Is it possible to combine the two sub-inboxes back to just one Inbox so I don't have to keep checking two?