Team Calendar Events have a preset category (but shouldn't)

[PixelMaster]

I've recently imported a Confluence Team Calendar into Outlook. Because the calendar's purpose is showing who's on duty for a certain task this week, I wanted to use Outlook's filtering capabilities to assign colors to events that are relevant for me.

However, it appears that all Confluence Team Calendar events have a pre-assigned category "other". Other calendars (such as my private Google Calendar that I embedded) don't have such categories.

This preset category is majorly annoying for me, as it serves precisely no purpose, yet it overrides any color that I assign via Conditional Formatting.

Does anyone have workaround for this? And in any case, would it be possible to remove this default category? I don't see any benefits to having it.