let page = document.getElementById('buttonDiv')
const kButtonColors = ['#3aa757', '#e8453c', '#f9bb2d', '#4688f1']
function constructOptions(kButtonColors) {
  for(let item of kButtonColors) {
    let button = document.createElement('button')
    button.style.backgroundColor = item
    button.addEventListener('click', function(){
      chrome.storage.sync.set( {
        color: item
      },function () {
        console.log('color is ' + item)
      })
    })
    page.appendChild(button)
  }
}
constructOptions(kButtonColors)