Server/Client status colors

Hi All,

Does someone know what the different colors of the server/clients mean? (See attachment)

I've got a problem with one client. After reboot of the client it keeps showing no server data no server connection.
Simatic shell is working fine, Ping is working, no firewall active, file sharing is working.

I notice the status of the screens. It keeps showing blue screen instead the green/blue ones. Also the header is not solid black. 

I created a new project but the status is the same.

I think the colors should give these.
Light green: Master server
Darker green: Standby Server.
Blue :Client

Where did I go wrong?