Don't chase megapixels! It takes a sensor of the right size to produce night color and even then every camera, video surveillance or still camera, needs some light to produce color at night. If you want more than 8MP I hope you have a really deep set of pockets. Cameras like that are available but are in the $2,000.00 and up range for the camera body. Then you need a lens, another $1,000.00 and an enclosure to put it in for another few hundred.
Any camera can be made to produce a nice still frame at night if the exposure time, shutter speed, is slow enough as in 1/10 second or even lower as far down as two or three seconds. That will produce a nice still image but as soon as motion happens all that you'll see is a blurred mess. Exposure times of 1/60 or 1/100 are needed to produce crisp motion video. The wrong sensor size on the wrong resolution will only produce a black screen if the exposure time is that fast.
Here's a guide for what works best at the moment in terms of sensor size versus resolution -
Disclaimer - These sizes are what the manufacturers advertise and may, or may not, be the true size of the sensor in the camera.
1/3" = .333" Great for 720P
1/2.8" = .357" (think a .38 caliber bullet) Great for 2MP
1/1.8" = .555" (bigger than a .50 caliber bullet or ball) Great for 4MP
1/1.2" = .833" (bigger than a 20mm chain gun round) Great for 8MP
The F stop of the lens is another key element. The lower that number the better. The smaller the lux number the better the low light performance. 0.002 is better than 0.02. The problem here is that manufacturers, as in all of them, tend to overstate the lux numbers to make their specs look better. Real world night motion video is the only way to truly evaluate a camera.