After the timeout specified in Admin->Configuration->My Store->Admin Session Time Out in Seconds has expired, the tab you are running your Zen Cart Admin in begins to flash **WARNING**. This is quite a horrible experience – it’s as bad as the old
<blink> tag in web pages from the mid 1990s. It’s a blight and a distraction. But the good news is, it’s also really easy to kill!
Edit the file
Around line 29, just after
add the line
'flashTitle' : false,
Refresh your admin, and from then on, no blinking!