Having multiple systems down sure sounds like a major outage to me. Not a complete outage, sure, but still a major one.
Red - Entire services are down
Orange - Partial outage of services, some functionality completely down
Yellow - Functionality performance degraded and may timeout/fail, but may also work
Greed - Situation normal
Green - Situation normal
Yellow - An outage more severe than usual
Orange, Red - would trigger SLAs, so not possible and therefore not implemented
Black - Status page down too, served from cache, renders as Green