SVG

Change color using JS

Inline SVG

source

<svg id="svg1" xmlns="https://www.w3.org/2000/svg"
  style="width: 3.5in; height: 1in">
    <circle id="circle1" r="30" cx="34" cy="34"
      style="fill: red; stroke: blue; stroke-width: 2"/>
</svg>

<!-- CSS should be used here instead of editing style. -->
<button onclick="circle1.style.fill='yellow';">Click to change to yellow</button>

Linked SVG

Note: styling on the object element does not affect the value inside. An iframe can be used too.

<object id="my-svg" data="image.svg" type="image/svg+xml"></object>

let object = document.getElementById('my-svg');
svg = object.getSVGDocument();
svg.getElementsByTagName('g')[0].setAttribute('fill', '#fff');