let ic = document.querySelector("svgitem") let a = ic.contentDocument a.querySelector("#svgitem").style.stroke = "white"
Let me explain the code above. The ic variable is the object containing the svg and then you use ic.contentDocument to access the contents why? Cause embedding a svg within an object would mean the same thing as an iframe and the only way to get it's content is through contentDocument (or contentWindow if you're working specifically with an iframe).
So with this you can modify attributes and all.
But there's a downside though, If you're running this on your browser on file:// i.e a local file, this might not work for some browsers like Chrome (v49.0) and Opera (v35.0) on both Windows and Mac.