If you want this

Open header.php and find
<meta http-equiv="Pragma" content="no-cache">
Before that place
<meta name="theme-color" content="#4285f4">
You can change the HEX code (#4285f4) with your theme color or with your favorite color
Here you can find HEX codes
http://www.color-hex.com/For apple devices too (Safari)

<meta name="apple-mobile-web-app-status-bar-style" content="black">

<meta name="apple-mobile-web-app-status-bar-style" content="black-translucent">