How can I generate two random colors on opposite sides of the color wheel?

Question

    var button = document.querySelectorAll('button');
    var drumCount = button.length;

    button.addEventListener('click', function(){
        this.style.color = '#'+Math.floor(Math.random()*16777215).toString(16));
        this.style.backgroundColor = '#'+Math.floor(Math.random()*16777215).toString(16)
  });

I have code that creates a random color, but I am wondering how to generate two random colors on the opposite side of the color wheel.

I know it seems trivial, but I have been at it for a while now, trying to figure this out. Any help is greatly appreciated