With the launch of Chrome 39, you’ll be able to use theme color of your websites or web applications to change the background of address bar/tool bar on your smartphones. Currently supporting Android(Lollipop+), iOS & Windows.
The code is pretty simple, you just need to use <meta> tag. Put the below code under your HTML <head> tag:
<!-- Chrome, Firefox OS and Opera --> <meta name="theme-color" content="#66bb6a"> <!-- Windows Phone --> <meta name="msapplication-navbutton-color" content="#66bb6a"> <!-- iOS Safari --> <meta name="apple-mobile-web-app-status-bar-style" content="#66bb6a">