How to put back the WAMP server Offline? Where is the option?

I installed Wamp 3.1.3 64 bit.
There are 3 icon colour basically in WAMP red,orange & green
These functionality is also known to me,so not describing.
But there is also another icon a green back with red dot and yellow lines. By google-ing I came to know that for Indicating The Server is Online. So Every thing is ok till now. I put my server Online.
But the problem is now how can i put the server back to offline? I can't find any PUT OFFLINE option. I tried with editting the

httpd.conf

&

vhost-htttpd.conf

files by setting everything-

Require Local

But Nothing changes . I also restarted the whole system. The Icon is same.
So how can i Put this back offline?