Peter Suber, whose Open Access Newsletter is a great source for anyone interested in OA has come up with a new classification of types of open access - he suggests the term 'gratis' where 'price barriers' are removed, and 'libre' for the removal of 'permission barriers'. However, since both words mean "free", I'm not sure that the distinction would be retained in general parlance.
However, I'm not sure it is necessary - the aim seems to be to overcome the problem that so-call "Gold OA" (in terms of journals) can mean those that are completely free, like Information Research, and those that use author charging to enable free access. I distinquish between these by reserving "Gold" for the author-charging mode, since it is that mode that has become associated with the notion in the mind of officialdom, and use "Platinum" for what Peter would now call "libre Gold" (or "Gold libre") - I think :-)
The situation is confused by the association between open access publishing and institutional or disciplinary repositories. While the latter provide open access to a proportion of the total literature in any field they are at present a somewhat disorganised collection of sources - some of which provide good coverage of an institution's output, some of which merely skim the surface. A couple of years ago I surveyed the repositories in the UK and found, for example, that although the University of Cambridge had more than 30,000 items in its repository only 16 were preprints of scientific papers. I regard repostitories as an interim solution: the future, inevitably, will be the "Platinum" publishing mode. The economics will drive inexorably towards this mode of scholarly communication - not, perhaps, in what is left of my lifetime, but inevitably.