While there are number of jailbreak tweaks available to customize the look and feel of the Notification Center, Vexillum seems to be the first jailbreak tweak that allows you to customize banner notifications.
Vexillum is quite a simple jailbreak tweak. It allows you to change the color and font of banner notifications. Vexillum is developed by the same developer who recently released Lorem – a jailbreak tweak that allows you to clear notifications with just a swipe.
After Vexillum is installed from Cydia, you can customize the banner notification via Settings ->Vexillum -> Color/Font.
The revamped notification system with Notification Center is one of our favorite iOS 5 features and jailbreak app developers continue to make it even better by releasing jailbreak apps and tweaks such as IntelliScreenX, Winterboard, Springtomize, NowListening, BBSettings, Lorem, ipsum, Notification Center Enhancer, ColorNotificationCenter.
Hat tip to iDB’s Cody!