A:AnswerNo you can not. Rg59 provides power to the camera also, wich the rg6 dose not have. Unless you run a power wire along with the rg6, but that is just too much hassle.
A:AnswerCameras can only use color vision if there is enough light to allow this mode. All security systems are black and white if there is no light.
If you want it to stay on color mode I would recommend adding an actual light near the camera to light up the area. Problem solved.