What colour is lightning?

What colour is lightning? In the following two photos, I had set the white-balance to Auto so I wonder what the colour would be if it had been set differently. The lightning bolts appeared to light up the sky blue.

My tripod was in the car and I was too lazy to do a proper setup outside, so as there was very little wind I decided to set my camera on the window sill, tilted slightly upward. Right in front of my lens is the window mesh screen however and as I wanted a wide angle shot, the screen was clearly visible. It would not be as clear had I zoomed in, but I wanted the wide angle shot.

For the shots, I set the lens to 18mm on manual focus set at infinity. It was too dark for auto-focus to operate. Aperture was set at f/10 for the first shot and f/14 for the second. ISO was set at 200. The CCD was exposed for 30 seconds in both instances.

Tonight was my first attempt to capture lightning.

I hope there will be thunder and lightning next weekend.