I've made a dark downanimation.zip (animation while phone is switching off) to replace the stock one from HTC. It's like the original one, but on dark background, to go with the dark splash screen and bootanimation that's floating around in the ARHD rom thread. Tested in my Desire HD (480x800). Don't know if someone else had already made this, but I couldn't find any...
Open root explorer, rename the file darkdownanimation.zip to downanimation.zip and paste it in /system/customize/resource. Then define permissions to rw-r--r--, like this:
Flash the darkdownanimation-flashable.zip in CWM.
Feel free to use it and comment on it! Thanks to Dude360 for making the flashable zip!