We have written recently about an issue with the colour depth of many Windows Phones dropping after the NoDo update, leading to banding when viewing gradients (see the picture above provided by Robert Varga and ipda.cz )
It seems somewhat of a solution has been found on XDA-Developers, which does however require a developer-unlocked device.
It appears all that needed is a registry edit to 3 keys which will restore 32 but colour to most areas.
The keys and values involved are:
HKLM\Drivers\Display\Primary\PrimBPP dword 32
HKLM\Drivers\Display\Primary\bpp dword 32
HKLM\Drivers\Display\Primary\PanelBPP dword 24
It appears some values result in performance issues, like the reason why Microsoft reduced the colour depth in the first place.
Read more about the hack at XDA-Developers here.
Thanks Santi for the tip.