OK - in which case it should be green when on and either orange or red when in standby, depending on other (network) settings and whether the maintenance cycles are running.
Did you do what I suggested and disconnect all equipment currently connected to the TV ? You need to do this in order to rule out any connected equipment as the cause.
If the problem is still there after a factory reset and with all external equipment disconnected, then it must be a fault.
Tough call - it's such a tiny fault to return a TV for but, on the other hand, it's important to know if and when the maintenance cycles are running so that you don't disturb them. It is possible to find out how many cycles have run via the status menu, but that won't help you avoid unintentionally stopping them if you don't know they're running.