Re: Green means everything's fine
Colour vision is something people forget, unless they have colour vision deficiencies (CVDs) themselves! You're absolutely right that indicators need more than just colours - shapes are handy, as are completely separate sections (if you have a box on the screen labelled "BAD STUFF" and put the alerts in there, it can help).
I'm fortunate in having a fairly mild red-green CVD that doesn't really affect me day-to-day, but given that some sources say it's reckoned to affect up to 8 per cent of men of northern European origin, that's a lot of IT guys who have trouble differentiating "good" from "bad" on a monitoring screen, particularly when the blobs/lines are close together. (I can point at something that's red, and I can point at something that's green, but give me an Ishihara plate with them all mixed together I'm doomed).
If you're about to scream "discrimination", red-green CVDs are a male trait - only half a per cent or so of women of similar origin have a red-green CVD. And you may also be interested that green traffic lights aren't green: they're greeny-blue because people who can't tell green from red often can tell the difference between greeny-blue and red because of the blue component.