One of the most disliked features by many of the new upcoming iOS 7 is the translucent panels. It can make text harder to read, makes distracting multicolored rainbows all over your screen, and can look just plain ugly in certain parts of the OS.
If you are one of the many who don't like the transparency or have reading difficulties due to the effect, and would rather have plain colors without the background colors seeping through, there is a setting to turn the translucency off.
In Settings you'll find an option called 'Increase Contrast'. Switching this to 'On', will remove all the transparency from iOS 7. Notification Center will now have a black background. Control Center will appear gray and not let other colors through, and so on...
Steps To Switch On 'Increase Contrast':
Settings > General > Accessibility > Increase Contrast > Switch to 'On'.