HTML5 - Beginners - Get rgb from string.html

<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width" />
</head>
<body>
  <div id="test"></div>
<canvas id="myCanvas" width="320" height="240" style="border:1px solid #d3d3d3;">
Use different browser.
</canvas>
  <script>
    var c=document.getElementById("myCanvas");
    var ctx=c.getContext("2d");


// stack overflow!
a= "RGBA(205,31,31,1)".match(/[\d\.]+/g).map(Number); //==[205, 31, 31, 1]


gameloop=setInterval(doGameLoop,16);

function doGameLoop(){
myCanvas.height = window.innerHeight-32;
myCanvas.width = window.innerWidth-32;
ctx.fillStyle="rgb(0,0,0)";
ctx.fillRect(0,0,c.width,c.height);
ctx.fillStyle="rgb(255,255,255)";
ctx.fillText("getting the rgb a color values in string..",10,10); 
for(var i=0;i<4;i++){
ctx.fillText(a[i],100,100+i*20);
}

}
</script>
</body>
</html>