WhatsColour is a background coloring for Whatsapp Web

whatscolour.js

( () => {
  const getChatTitle = () => document.querySelector('h2.chat-title > span').innerText;
  
  const colour = ( WhatsColour ) => {
    let contains = WhatsColour.colorList.findIndex( c => c.name === WhatsColour.getChatTitle() );
    if(contains > -1){
     document.querySelector('div#main').style.backgroundColor = WhatsColour.colorList[contains].color; 
    }
  }
  const getPerson = (color) => ( { name: getChatTitle(), color } );
  
  const setColor = (colorName) => 
    WhatsColour.colorList.push(getPerson(colorName)) | colour();
  
  const WhatsColour = {
    getChatTitle,
    setColor,
    colorList: []
  };
  
  window.WhatsColour = WhatsColour;

  document.querySelector('div.chatlist.infinite-list')
          .addEventListener('click', colour(WhatsColour));
})();