lite up the cloud, was wide moved side to side

I was driving down 287 south, pass Laporte,it was dark, and a cloud lite up in a bright white then a green hue, (it was like when you see heat lighting in a cloud) It moved swiftly side to side, it went from bright white to leaving a ring of green around it, I watched it for about a minute then it shoot up and disappeared. I drive semi, seen a lot, but never anything like this, It was large, wide. very bright light, not flashing it was constant. then a green hue would come off it. strange..