[css] Why can't I use background image and color together?

Hello everyone I tried another way to combine background-image and background-color together:

HTML

<article><canvas id="color"></canvas></article>

CSS

article {
  height: 490px;
  background: url("Your IMAGE") no-repeat center cover;
  opacity:1;
} 

canvas{
  width: 100%; 
  height: 490px; 
  opacity: 0.9;
}

JAVASCRIPT

window.onload = init();

var canvas, ctx;

function init(){
  canvas = document.getElementeById('color'); 
  ctx = canvas.getContext('2d'); 
  ctx.save();  
  ctx.fillstyle = '#00833d'; 
  ctx.fillRect(0,0,490,490);ctx.restore();
}

Please let me know if it worked for you Thanks