I've been well above the minimum requirement throughout the period the ratio was showing in dark red, so it looks like there may be a gremlin in the coding somewhere. What seems to have set the ratio colour back to white is the fact that I passed the 250 GB download mark today (unless that's just a coincidence).
That definitely shouldn't occur and likely was a gremlin - perhaps relating to our recent reconfiguration changes. The system should update the ratio red signal within 10-15 minutes after restoration of the minimum ratio. Sorry about that! Glad it reset for you eventually.