<link rel="icon" sizes="any" mask href="website_icon.svg">
To specify the color the icon should be displayed in, add the theme-color meta element to your webpage:
<meta name="theme-color" content="red">
How to customize icons for Pinned Tabs in OSX 10.11 El Capitan
ECMAScript 6 Enhancements & Unprefixed CSS Properties.
The properties in Newly supported ECMAScript 6 properties are now fully supported by Safari, without the -webkit- prefix.
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