-Color Keyboard or Color Keyboard HD
There are two ways to get this tweak, one is by just getting it off the Source from BigBoss. another way is to use this following Source:
Here you will find the full version of the Color Keyboard but the other ones work just as well.
After installing the Color Keyboard, Cydia will ask you to respring your IDevice, the statement left is that you need to Reboot, this is not true for i only used the respring method and it worked just fine. After the Respring, open up your settings and locate the Color Keyboard tab and set your themes and settings and then respring again and your done.