Thanks! That was a great tip!
v4l2-ctl -d /dev/video0 --list-formats-ext
Pixel Format: ‘MJPG’ (compressed)
Name : Motion-JPEG
…
Size: Discrete 1280x720
Interval: Discrete 0.017s (60.000 fps)
…
Pixel Format: ‘YUYV’
Name : YUYV 4:2:2
Size: Discrete 1024x768
Interval: Discrete 0.100s (10.000 fps)
So I am presuming gstreamer took YUYV device data nd processed it thinking it was UYVY, hence the warped colors?