Chris,
The UP or DOWN WRT stations on the ognrange map refers to whether the station is ‘UP’ i.e. active or ‘DOWN’ i.e. inactive, but it is driven by data being received or otherwise by the OGN servers. The stations can often be functioning fully, but still show on ognrange as ‘DOWN’, if for example there is no recent traffic, so take the colour codes with a pinch of salt.
Don’t confuse this with the UP-OGN labels which appear on your Nav Screen via PilotAware which indicate that this is a contact visible via ‘Uplink’ from a PAW OGN-R Rebroadcast unit.
Regards
Peter