Had an issue where several cameras (5) seemed to be stuck in night Mode: i.e. The image was only showing in black & white.
Going to the CAmera GUI to select Day mode, just gave a Black Image.
Setting it to Auto Iris, was the same as being in Night Mode.
So no color image was available from the camera.
Turned out that the Lens Iris cable was not connected properly to the Camera Body and was not visible as the camera was in a housing.
After Firmly connecting the cable to the camera body, the Issue was resolved!