I recently noticed that there are some apps in the iOS app store which claim to be able to change the color of both the status bar and the dock of the iOS Springboard. This seems impossible because such system-wide changes are almost never allowed by Apple, and after some googling I have found no answer. Here is an example of a dock color changing app, and here is an example of a status bar changing app.
Searching SO appears to bring up code for changing the status bar in the app, which is not very difficult, but not outside of the app. However, this functionality has clearly existed for a while, for example in the Voice Memos native iOS app, which turns the status bar red while recording.
Lastly, apps such as voice Memos and the native Music app appear to bring up special controls or animations when in use on the lock screen. It is possible to use the built-in iPod lock screen controls for other music apps, (see here), but I have seen no examples of custom lock screen app controls that made it through the app store.
Sorry to pack so many questions in one, but these are all examples of apparent across-system functionalities which I and likely many others would like to replicate, and thus merit attention.
As a postscript, is it possible that the color changes in dock and status bar are done but changing those parts of the wallpaper extremely so that when seen through the translucent UI they look like less bright but still noticeable colors? Thanks!
All of the examples app you have given just change your background. Since the statusbar and dock are translucent they change color when you set the background made with these app as you background.
The red bar from the voice memos is a system indication that some app is recording, this is not something you can change. The The status bar will become green when you there is an active phone call going and you open any app. The same with tethering.
You can not add any custom lock screen controls, there is no option for this in the SDK.