defog fog defogging

Dahua cameras with defog capabilities have this function set off as the default. With cameras that support this feature, are there any known disadvantages / compromises should the defog be active?

Hello, If there is anyone here with experience with the 4K Hikvision cameras, I am having difficulty getting the camera to do these three things at one time: 4K, Color, Defog. As soon as I turn defogging on, the image goes to grayscale. This does not happen when the camera is in 1080 mode...