Lately, open-access seems to be flourishing somehow, with the condition that those who made money out of publishing, keep making them, and those who paid for the "published" research keep paying twice for it (once for the research to be done, and once for it to be read).
That's why open-access comes in various colours to you, diamond, green, gold, shiny, cacao etc.
Also a lot of high-level people seem to be concerned by open-access, even supporting it in some twisted way (e.g. the author pays kind of open-access).
Obfuscation is endemic.
Despite the apparently complicated issues, this is a simple phenomenon, and time is ripe for the public research to be available to the public who paid for it. No further costs, no further discussions, no further qualifiers and colours. The existence of internet enables it.
There are two simple and cheap things to be done here:
1. Forbid public research personnel to hand over the copyright to publishing companies. A law phrase is enough to cover that. Work circulates under a CC-BY license at all times.
2. Understand that the flow of a scientific article needs to change, from the traditional way: author->peer review->publisher on paper->libraries to author->peer review->digital library->(optionally) publisher on paper. This means: only fund public research if it gets published in a digital library when it's done.
Note also the change from libraries to digital library, plural to singular. There's no reason to have more than one digital library per country. Moreover, the digital library is self-sustaining because publishers on paper will have to pay for their commercial access to the digital library to assemble works on paper for various interested parties.
Then implement a public access digital library of publicly funded research results per language.
It's easy, and cheap: such a "national" library doesn't need more than 200 msq of office space populated by 4 persons and more than, say, 10 TB of storage capacity for now.
Anything else, or more, is plain bulshit.
If you don't believe me, hire me and I'll prove it (I will only work for Greece, Portugal, Spain, Romania, France, Belgium or EU institution with offices in one of those countries), given the law phrase above is official and the obligation for the publicly funded published research to be passed to the "national" digital library).