Now that you have a more capable camera, look into using what is called a neutral density filter. This is essentially a dark piece of glass that will permit you to extend the time the shutter is open.

Also see if your camera has a noise reduction feature. This will help eliminate the color noise in the pix. In addition, setting the camera to the lowest ASA or ISO it can be set to will go a long way to eliminate color noise.

Lastly, carry a 1 iron golf club with you when photographing lightning....