So here i am attaching some screen shots to refer app that i am using for galaxy theme and it is customizable and it has most unique features..
App - HEX INSTALLER
As you can see it turns background totally black and gives much richer look on your galaxy.
You can also change colors of icons in the notification panel.
Material icon pack is looks very awesome with this theme.
I used AOSP DAY/NIGHT Plug-in.
