Attach style to svg file by
//HTML
<style type="text/css" rel="stylesheet" href="./style.css"></style>
<div class="wrapper">
<svg>
<use xlink:href="SVG PATH + #hoge"></use>
</svg>
</div>
//SVG
<svg>
<symbol id="hoge">
<path class="fuga" ..........></path>
</symbol>
</svg>
//style.css
.wrapper{
color: red;
}
.fuga{
fill: currentColor;
}