[FFmpeg-user] Detect grayscale intervals or images in a video with ffmpeg

[Num]

Hello everyone,

I know the blackdetect filter which detects black intervals in a video.I
can not find any filter that works identically to detect grayscale/"black
and white" intervals in a video.Can I do this with one or a combination of
the built-in ffmpeg filters?
Thank you,Numid