Storyline 360 - Change State of

Hi there, i am new to Articulate and I am creating training videos and i have broken down all my sections into Buttons.  I am trying to make it so that when you click on a button to get into that section it shows as being viewed, also changing the colour of the button.  I have followed the guidance on how to do this including edit states and applying triggers but it does not seem to work.  What am i doing wrong or not doing?  Any help would be much appreciated.  Thanks Beverley