color change function

ui.js

function changeColor(classname, color) {
  const elements = document.getElementsByClassName(classname)
  for (let i = 0; i < elements.length; i++) {
    if (elements[i].localName === 'div') {
      elements[i].style = `background-color: ${color};`
    } else {
      elements[i].style = `color: ${color};`
    }
  }
}