S8+ navigation bar is multi coloured and won't change

[Android Central Question]

My navigation bar used to be transparent/dark but all of sudden its changed to this multi coloured (almost rainbow like) state, and I've been unable to change it back. I'm almost certain it's a glitch because at times it seems to revert back to its original colour for a few seconds but then it goes back to this rainbow like bar. I've tried restarting my phone, applying the current theme and manually changing the colour of the navigation bar within the settings but nothing has worked. I've also tried changing the colour of the rainbow navigation bar with apps such as NavBar but any changes made seem to be overrided with this strange colour that just doesn't go away. Any tips?