Hadn't considered this before...
I did re-seed last Spring after core-aeration. By far... What is most confusing to me is that both the light and dark blades are Kentucky blue.
Does your theory fit?
Originally Posted by Skipster
I'm going to ask a different question. Has there been any seeding done recently?
When seeding too heavily, plants compete with each other for resources and don't mature very well. This could also introduce different cultivars of the same species, which may have color variations.