Winter Combat Jacket, Pullover, KF Shirt or Combat Green. 6-7 degree is not really cold in the UK....It may be for HK as you do not use to it.....
This is what I wear when I was in the service in the cold weather. If it is really really cold then I use the Army towel over around the neck and it keep me really warn.
Now in the UK is about 10 degree in the afternoon and I only take a T Shirt or Shirt in door and another jacket outdoor.