Perceptions of light and dark ...black and white are about the caster himself. It is the intention that makes something dark or light.
If you have mayhem and destruction in mind, then thats your intention. Tailor the spell towards this intention using components that work for you or appeal to you or have to do wit hthe path your on.
I get the feeling youre asking for something more specific and you can reveal what you want in your posts, obviously, but it still seems kind of vague to me. But then maybe im not that smart ; )
Anyways, Darkphoenix, good luck with your work. I hope i gave you some ideas