Here’s an interesting question. If you wish to indicate whether a valve is open or close, which one of the following would you use:
Here’s an example where the same company uses a red valve to indicate both open and closed status. Let’s get the obvious out the way: a given facility has a standard method of indication. For the company in question, onshore facilities have red indicating open valves, offshore facilities use green.
Now, why two different standards be used? You have to see ‘certain points of view’ (since we’re using Star Wars cliches here):
- If you were an electrical engineer, red means energized and equipment is in its working state. For a valve, this would mean the valve is open.
- If you were a process engineer, you’d choose green for go.
So, the colours chosen for your mimic panel or basic process control system (BPCS) display would be whether the process or electrical engineers spec’ed out the system.
Engineers, RTFM.
Wata - Malaysian Oil and Gas Engineer 
Jabba works on black and white drawing…. moreover, jabba is colour blind…. only can distinguish colour of money and blood of enemies….
the control room jabba visited was using black and white TV……