How to make transparent color white instead of black in html2canvas?

I modified temporary: _html2canvas.Util.isTransparent from

_html2canvas.Util.isTransparent = function(backgroundColor) {
  return (backgroundColor === "transparent" || backgroundColor === "rgba(0, 0, 0, 0)");
};

to

_html2canvas.Util.isTransparent = function(backgroundColor) {
  return (backgroundColor === "transparent" ||
    backgroundColor === "rgba(0, 0, 0, 0)" ||
    backgroundColor === undefined);
};

and after that it was enough to call html2canvas with background parameter set:

html2canvas(screenshotElement, {
  background: '#FFFFFF',
  onrendered: function (canvas) {
    // ...
  }
});

For me... it makes sense to consider transparent a background that is undefined.

I'd say, it's even simplier now(30/05/18) - just pass backgroundColor: null in html2canvas options:

html2canvas(
    document.querySelector("#some-id-to-export"),
    {backgroundColor: null}
).then(canvas => {$("#id-to-render-transparent-bg-img").html(canvas);});

Try this

var body = document.getElementById("body") 
$(body).html2canvas({background:'#fff', onrendered: function( canvas ) {  
 var urlData = canvas.toDataURL("image/jpeg");  
}});