Coloring SVG content url with css - html

Question

I have a button set up like this:
<button class="buttonclass"><i class="iconclass plus-icon"></i></button>
My css classes look like this:
.buttonclass {
width: 30px;
height: 30px;
text-align: center;
position: relative;
border-radius: 20px;
background-color: #1DBE60
}
.iconclass {
width: 20px;
height: 20px;
margin: 7.5px;
}
.buttonclass .iconclass {
margin: 0;
position: absolute;
top: 50%;
left: 50%;
transform: translate(-50%, -50%);
}
.plus-icon {
content: url(http://uxrepo.com/static/icon-sets/mfg-labs/svg/plus.svg);
}
How can I change the color of the 'plus-icon' with css if it is an SVG? I have tried adding fill classes to the svg, color classes, background-classes, etc.
Here is a plunk:
http://plnkr.co/edit/6fLYQlpFmDdf7aWenBtp?p=preview

Answer 1

If you're happy to add one extra class (for the color of the plus icon) then here's a CSS-only solution using the currentColor CSS variable:
.buttonclass {
width: 30px;
height: 30px;
text-align: center;
position: relative;
border-radius: 20px;
background-color: #1DBE60
}
.iconclass {
width: 20px;
height: 20px;
margin: 7.5px;
}
.buttonclass .iconclass {
margin: 0;
position: absolute;
top: 50%;
left: 50%;
transform: translate(-50%, -50%);
}
.plus-icon {
background-image:url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><rect x="0" y="0" width="8" height="8" fill="rgb(29,190,96)" /><rect x="0" y="12" width="8" height="8" fill="rgb(29,190,96)" /><rect x="12" y="0" width="8" height="8" fill="rgb(29,190,96)" /><rect x="12" y="12" width="8" height="8" fill="rgb(29,190,96)" /></svg>');
background-color: currentColor;
border: 1px solid rgb(29,190,96);
border-radius: 15px;
}
.white {
color: rgb(255,255,255);
}
.yellow {
color: rgb(255,255,0);
}
.green {
color: rgb(0,255,0);
}
<button class="buttonclass"><i class="iconclass plus-icon white"></i></button>
<button class="buttonclass"><i class="iconclass plus-icon yellow"></i></button>
<button class="buttonclass"><i class="iconclass plus-icon green"></i></button>

Answer 2

You have to put the svg inline but consider using the <use> element instead so you can use an icon multiple time by referencing it:
http://tympanus.net/codrops/2015/07/16/styling-svg-use-content-css/

Answer 3

I ended up here looking for a way to color a svg icon. The most voted answer didn't helped me so after some googling i came across to this interesting codepen.
Long story short i colored my svg icon using this css:
.plus-icon {
-webkit-mask: url('../images/plus.svg') no-repeat 50% 50%;
mask: url('../images/plus.svg') no-repeat 50% 50%;
-webkit-mask-size: cover;
mask-size: cover;
}
.white {
background-color: rgb(255,255,255);
}
Update:
Not working with IE.