There has been a photo of the LG Nexus 4 posted online in white. The shot of the phone was sent to PhoneArena by a tipster who wishes to remain unknown and it shows what is said to be the LG Nexus 4 in white with a silver trim LED flash. Of course at the moment there is nothing to guarantee that this is the real deal, but it does look authentic.
White LG Nexus 4 pictures leaked, unclear about rear
One thing in the favour of it being the real thing is the difficulty that would have been involved in fabricating the image at that size (it is huge and of a very high resolution). However we only see the back.
There have been rumours of a white LG Nexus 4 being made ever since the black version of the device came out. LG have a white version of the LG Optimus G, which is the handset that the LG Nexus 4 was based upon. The two devices before the LG Nexus 4 were also available in white i.e. Samsung Nexus S and Samsung Galaxy Nexus, albeit in quantities that were limited and they were actually oreo (white rear with black front).
So at this time we have to assume that since the two Nexus phones before it only had a white rear, the same may happen with the LG Nexus 4 too.