From the command line, you can check the process status of the SpectroSERVER:
[spectrum@speclinux ~]$ ps -eaf | grep Spectro | grep -v grep
spectrum 3089 2329 65 10:37 ? 00:00:04 /usr/Spectrum/SS/SpectroSERVER
You can also see if the server is starting, running, stopping, or stopped by tailing the $SPECROOT/SS/VNM.OUT file:
[spectrum@speclinux ~]$ tail -f /usr/Spectrum/SS/VNM.OUT
Sep 27 10:37:48 : Please wait. SpectroSERVER
is loading landscape 0x400000 at precedence 10...
Number of models loaded : 172
Sep 27 10:38:02 : /usr/Spectrum/SS/SpectroSERVER
is now ready on port 0xbeef...
I don't have many models on my little test system here but you'll see the number of models loading increase as it loads, so that would correspond to the starting (yellow). When you see "is now ready on port 0xbeef...", that's when the Control Panel indicator would go from yellow to green.
Similarly, when the server is stopping:
Sep 27 10:41:33 : SpectroSERVER has received shut down signal - scheduling shut down
Sep 27 10:41:33 : /usr/Spectrum/SS/SpectroSERVER is shutting down...
Sep 27 10:41:34 : Closing all client connections...
Sep 27 10:41:34 : Stopping CORBA communication...
Sep 27 10:41:36 : Stopping /usr/Spectrum/SS/SpectroSERVER activity...
----- NOTE --------------------------------------------------------------
CA Technologies recommends that the SpectroSERVER be
allowed to complete the shutdown process.
Database corruption may result if the SpectroSERVER is prematurely stopped.
------------------------------------------------------------- NOTE ------
Sep 27 10:41:36 : waiting for model activates to complete...
Sep 27 10:41:36 : waiting for model destroys to complete...
Sep 27 10:41:36 : Closing /usr/Spectrum/SS/SpectroSERVER database...
Sep 27 10:41:36 : /usr/Spectrum/SS/SpectroSERVER has successfully shut down.
The period between the "SpectroSERVER has received shut down signal - scheduling shut down" and "SpectroSERVER has successfully shut down." would line up with when the Control Panel should show stopping/yellow. Once you see the "has successfully shut down" message and don't see the SpectroSERVER process running, that would correspond to the inactive/blue state:
[spectrum@speclinux ~]$ ps -eaf | grep Spectro | grep -v grep
[spectrum@speclinux ~]$
As far as terminated/red, you would typically see an error message in the VNM.OUT file and the SpectroSERVER process wouldn't be running. If there is no error message, then if the SpectroSERVER process isn't running (use the ps commands from before) and you don't see "SpectroSERVER has successfully shut down." at the end of your VNM.OUT file, that would also indicate that the server has terminated and would show red in the Control Panel.
Hope that helps.
-Rob