I can't really solve your problem, dynamic lights are limited in terms of what they can do, to make it harsher I would simply increase the brightness of the colours used or increase the range of the light, thats about it. You can alos make it a spot light if you need to.

Just Because Your Paranoid Doesn't Mean They Aren't After You...Because They Really Are <<< It took me around 90 seconds to work it out.