Apple is extremely strict when it comes to modifying your iPad, iPhone, or iPod touch. For example, let's look at the dock on iOS 7 devices. You've only really got two options for the dock background, either the default frosty translucent one, or the dark gray version. That's it, and the dark one will also change the look of other things on your device.
Ultimately, it feels like these two docks limits and shrinks the home screen size. It's not that big of a deal, but the real issue is that we're not given a choice; we can't dictate or select another alternative in the settings. However, if you jailbreak your iOS 7 device, you can add one more to the list—a completely transparent background—which expands the look and feel of your home screen.
Head into the Cydia app, which is pre-installed after jailbreaking, select the Search tab, look for DockShift, and install it.
After the tweak is installed, go into your device's Settings and look for the new DockShift option. From here, you will select the Transparent style, then enable.
It's that easy, but keep in mind, this tweak will not work with the iPhone 4 or lower, but it will work for the iPhone 4S or higher running iOS 7.
Enjoy having a much cooler and well-deserved dock background. For troubleshooting help or feedback, leave a comment.