Is there any particular standards the regions are instructed to follow? It all seems so much of a mish mash!
I guess this is one of the downsides for the BBC over ITV. Am I correct in thinking ITV graphics are centralised in Birmingham where as in the BBC each region handles there own?
Each BBC region certainly generates its own content graphics on-site (though sub-regions may share design facilities with their 'mother' region sometimes)
Opening titles, historically, have varied. Some refreshes have involved Network, Nations and English regions getting titles all made by the same team (though not always introduced simultaneously). Other refreshes have been locally generated.
There is always a tension between consistency/uniformity and local editorial variation, and local teams often have a better understanding of their audience than a team covering the whole country would (particularly when featuring local landmarks, place names etc.).
Given that only a small number of TV enthusiasts regularly watch multiple regions, the important thing is that the network brand and each local variation look and sound to be part of the same brand. It's far less important that every region looks identical - as most people only watch one region.
What SHOULD be specified nationally (and adhered to) is a common branding style guide (and someone in each region who understands it well enough to enforce it) - though this isn't always the case it seems. (With some slightly random font choices being made in some cases...)