Synoptic Display: Icon Colour to Reflect Equipment Status

As a scientist, I want to be able to look at the synoptic display and see at a glance the status (normal, out-of-limits/error) of an item of equipment.

'''Acceptance Criteria'''
1. The colour of an icon on the synoptic display changes to indicate its status.

'''Notes'''
1. What colours should we use? For example:
1. Normal: Green
2. Out-of-limits: !Amber/Orange
3. Error: Red
4. What colour for "no status" or "disconnected" or "not switched on"?
1. What about configurable colours (for colour-blind people)?