[Mike]

I guess it's more noticeable now that most regions have an identical set. Any variation in lighting or how one set looks stands out more when you can see 6 other examples of the same space.

Oh totally, and what makes me think it's more than simply the lighting is this
twitter.com 

The grey panelling on the studio set are actually on the screens and not real, the Birmingham studio they look dirty grey and washed out whereas the others don't. Might just be that since they upgraded the studio cameras they haven't racked them correctly (and to be honest if an IGS Gallery is inbound why would they necessarily bother for the sake of aesthetics) - or they've been done by someone using a dodgy reference monitor.