The Chip Cydia tweak is a complete notification banner customizing platform that allows you to edit the background color (solid color or gradient effect), border color, border width and even text color. And while changing the color of various aspects of your notification banner you can choose from pre-set colors or use the RGB sliders.Another neat feature of the Chip Cydia tweak is that you can customize the animation of your notification banners and also the sound of the notification

It costs $1.99 from BigBoss repo

*Kudos to iJailbreak