For instance, you can use yellow for "warning/important" level and red for "critical" level, and lights-only for staging environment and light & sound alarm for production environment, for instance. Pretty expensive, though.
I understand that sentiment is popular on HN, but not listing prices is pretty standard for B2B. At least in Japan (where Patlite is based), most businesses will not discard a potential vendor just because they don't list prices on their webpage.
http://www.patlite.com/product/category0002_000000.html
For instance, you can use yellow for "warning/important" level and red for "critical" level, and lights-only for staging environment and light & sound alarm for production environment, for instance. Pretty expensive, though.