Well, damn, we might not be correct on the date for it being blue. I found another image where it is blue and the image details show it was from September 2014.

Tuesday, September 2, 2014, 3:49:50 PM (Camera setting, not necessarily the time of day)

https://en.wikipedia.org/wiki/London_Eye#/media/File:London_Eye_Night_Shot.JPG

Online photo details:

Yoga Balaji - Own work

London Eye, a giant Ferris wheel near the London County hall building, at night

CC BY-SA 4.0

File:London Eye Night Shot.JPG

Created: 1 July 2011