$color-white: #fff;
$color-not-white: #f00;
.ico {
color: $color-white;
}
.ico:hover {
color: $color-not-white;
}
<svg class="ico" viewBox="0 0 42 42" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<circle cx="20" cy="20" r="19" stroke="white" stroke-width="2" />
<g class="color-change">
<circle cx="19.5" cy="10.5" r="2.5" fill="currentColor" />
<circle cx="19.5" cy="19.5" r="2.5" fill="currentColor" />
<circle cx="19.5" cy="28.5" r="2.5" fill="currentColor" />
</g>
</svg>
$color-white: #fff;
$color-not-white: #f00;
.ico {
color: $color-white;
}
.color-change:hover {
color: $color-not-white;
}