Im not sure if it's year round, but CO uses two different routes for the HKG flights.
The flight from EWR-HKG takes the polar 2 route straight North from EWR almost directly over the Pole then down Russia and across China.
The route from HKG-EWR takes the more conventional routing over Alaska and across Western Canada.
I think they do this because the winds are favorable on the return leg, and the Russian Governement charges for the use of the Polar route. So not using it both ways saves money.
Eastern Air lines flt # 701, EWR-MCO Boeing 757