white balance mode: regional custom?

under white balance, what is the "regional custom" mode setting? couldn't find any info on this setting.
From dahua manual
When the “Mode” is set as “Regional Custom”, it is to set customized area, the system can compensate white balance to different color temperature of the images in the area, which is to make the image color normal.
 
  • Like
Reactions: 1.21 jiggawatts!
From dahua manual
When the “Mode” is set as “Regional Custom”, it is to set customized area, the system can compensate white balance to different color temperature of the images in the area, which is to make the image color normal.

makes sense.

my problem was that i was using firefox to access the the camera UI and my main stream is h265 and i didn't get regional custom yellow box outline. i used the nacl web viewer and set the main stream to h264 and i was able to see the regional box and move it around.