color_depth information incorrect

[phuclv90]

My MBP M2 has XDR display but color_depth is always 8, even when I'm viewing HDR contents

 mode 54: res:1728x1117 hz:120 color_depth:8 scaling:on <-- current mode

It should be 10-bit instead. When I plug in an external monitor and toggle the "HDR" switch the values are still the same

$ displayplacer list | grep 'current mode'       # external monitor via display port
  mode 59: res:2560x1440 hz:60 color_depth:8 scaling:on <-- current mode
  mode 54: res:1728x1117 hz:120 color_depth:8 scaling:on <-- current mode
$ displayplacer list | grep 'current mode'       # external monitor via HDMI, HDR on
  mode 118: res:2560x1440 hz:60 color_depth:8 scaling:on <-- current mode
  mode 54: res:1728x1117 hz:120 color_depth:8 scaling:on <-- current mode
$ displayplacer list | grep 'current mode'       # external monitor via HDMI, HDR off
  mode 118: res:2560x1440 hz:60 color_depth:8 scaling:on <-- current mode
  mode 54: res:1728x1117 hz:120 color_depth:8 scaling:on <-- current mode