Exclamation next to WiFi symbol, means it's connected to WiFi but it can't connect to the internet proper, e.g. "free" WiFi that has a landing, payment or login page, that you may have to deal with in the browser before it can access the internet. Why it's light brown, I have no idea, but it might be something particular to the OPO, Oxygen OS it runs. Another indicator that some might not recognize is an "N" symbol, which means the phone's NFC is on. You could probably Google something like "Android Lollipop FAQ", that might give you some more information about them.