Wired Intelligent Edge

When I do a show spanning-tree I get the following result. If the switch priority is 0 then why would the CST root priority have a different MAC address? Can I change the priority of the CST root

Multiple Spanning Tree (MST) Information

  STP Enabled   : Yes
  Force Version : MSTP-operation
  IST Mapped VLANs : 1-4094
  Switch MAC Address : 8851fb-d08a00
  Switch Priority    : 12288
  Max Age  : 20
  Max Hops : 20
  Forward Delay : 15

  Topology Change Count  : 12,161
  Time Since Last Change : 9 mins

  CST Root MAC Address : 000e7f-50a2c0
  CST Root Priority    : 0
  CST Root Path Cost   : 240000
  CST Root Port        : B24

  IST Regional Root MAC Address : 8851fb-d08a00
  IST Regional Root Priority    : 12288
  IST Regional Root Path Cost   : 0
  IST Remaining Hops            : 20

I'm not sure I entirely understand the question: the switch you are logged onto has priority 12288; the CST root has priority 0. If you want to change the priority of the CST root switch, do it from there, if you're sure you want to change the root.