There are so many types of cloud formations that we could talk about them for weeks on end and we haven't even hit my favorites. Hopefully we'll do that next week. I'm hope you're seeing the formation of clouds depends on what part of the atmosphere they're in. They also depend on several other factors too. Like the cirrostratus. The cirrostratus are high based clouds "when convectively stable moist air cools to saturation at a high altitude" (http://en.wikipedia.org/wiki/List_of_cloud_types). Sometimes, websites say it best, especially when it comes to science.
The thing about cirrostratus clouds, and I'm sure you've noticed it yourself, is that they almost always take up the entire visual when they move in. Since I don't have a picture available, let me try to describe it to you. It's like a wave riding across the sky. Well, riding depends on how fast the cloud is moving. The reason it takes up so much space is usually because a frontal line is pushing it, so depending on how quickly that frontal line is moving depends on fast the cloud moves.
As the cloud gets closer, depending on the weight of precipitation, which depends on the temperatures and whether or not they're clashing with other fronts, the cloud formations can begin to look lower, heavier and darker. This frontal cloud can mean rain or snow. Here is a great link to a time lapse video http://youtu.be/gNGhvbjBVQw.
Here is another video.
The optical phenomena that you see is most likely from the cloud formations changing and dropping into the lower atmosphere. It seems to me that as the clouds thicken and more ice crystals form, the sun reflects off of them like a prism causing the beautiful spectacle.
The videos I shared are of a more dramatic nature of the cirrostatus and come along with other cloud formations. As I said above, much depends on the many other factors. However, there are times when the cirrostatus appears to be nothing more than a thin sheet of lace.
I love how dictionary.com describes the cirrostratus-- appearing as a whitish and usually somewhat fibrous veil.
Writing prompt: A slight breeze tugged on the linen as Nonnie secured it to the clothes line. She glanced toward the western sky. A thin sheet of delicate, white lace, much like her grandmother's curtains, spread from the north to the south. However, that beautiful picture was not what caused her breath to hitch in her lungs . . .