That would be a lot of different colours.
White shirt, burgundy tie, navy suit and a fourth colour? A white pocket square would be fine. That matches the shirt.
actually ive suggested to people new to PS that to start with a plain white PS folded OR go with something dark with some subtle colour highlights to ease your way in.
I still dont wear a PS in most business situations here as most of my clients dont even wear a tie or jacket and id come across too "bling" or showy with a ps as well