If you want to add some spiced up colorization to your iOS 7 keyboard, then you'll want to check out a new jailbreak tweak called DathKeys
by iOS developer Orangebananaspy.
As you can see from the example screenshots above, this tweak will let you colorize your iOS 7 keyboard in various ways. The tweak lets you adjust the colors of the characters on your keyboard, the background color of your keyboard keys, the color of highlighted keys, and even colorize the shadow of your keys for a cool glowing effect.
DathKeys adds a preferences pane to the Settings application where you can get started with adjusting its color options to your liking. From the main preferences pane, you can enable or disable the tweak on demand. You will also see individual cells for adjusting the options for your individual keyboard elements. At the top right of the preferences pane is a little floppy disk icon, which you will need to tap on every time you make changes in order to save your changes. It will respring your device:
As you go into the individual preference cells, you will find RGB color sliders for red, green, and blue, which can be used to colorize your keyboard elements to your liking. There is also an alpha slider that you can use to adjust the transparency. You can use the "What's this?" button at the bottom of each preference pane in order to see what part of the keyboard that you will be adjusting when you change the color slider settings:
With all of these options being made available, this tweak is already an awesome tweak for customizing your keyboard, the developer says that even more is coming. We would like to see the ability to change the background color of the entire keyboard interface at some point.
If you would like to give DathKeys a try, it's available right now in Cydia's BigBoss repository for just $1.50. The tweak is compatible with iOS 7.1 and later.
iPhone 5 running iOS 7.1.2, iPhone 4 running iOS 7.1.2
You can watch our video review of DathKeys below: