Use JavaScript to find element by its CSS property value

How do I find the element by matching its CSS property value?

For example, if the background color of the element is green, then do something…

const elm = document.getElementsByClassName('elm');

[...elm].forEach(function(s) {
  //find the element which background color is green
  
  //then console.log(theItem)
})

.elm {
  width: 200px;
  height: 100px;
}

.elm1 {
  background-color: red;
}

.elm2 {
  background-color: green;
}

.elm3 {
  background-color: blue;
}

<div class="elm elm1"></div>
<div class="elm elm2"></div>
<div class="elm elm3"></div>