The value is to remark When green action is remarking.
For remarking DSCP, the range is 0~63;
For remarking IP Precedence and MPLS EXP, the range is 0~7;
Only software QoS support this node.
255 is returned only when getting value from hardware QoS or when action being pass,discard of software QoS.
255 can't be set.