Notice the color change of Chrome and the status bar when you visit certain sites on your mobile device? For example, on Android when you head over to say the forums of XDA-Developers or Victoria's Secret.

Turns out this is quite easy to achieve on certain mobile browsers and operating systems. Just add the following to the <meta> tags section of your site:

Chrome, Firefox OS and Opera
<meta name="theme-color" content="#4285f4">

Safari, iOS
<meta name="apple-mobile-web-app-status-bar-style" content="#4285f4">

Windows Phone
<meta name="msapplication-navbutton-color" content="#4285f4">