The "allowed" (toegelaten) spelling of 1954 included many deviations from phonetic, as compared with "preferred" (voorkeurspelling) orthography. The variations many of which originated in the adoption of foreign words* were the target of "preferred" Dutch," which standardized usages according to a modern set of accepted spelling representations of the sounds within the language. There are exceptions to this statement, but it's generally true.
The Green Book itself it not the legal arbiter of proper Dutch, but is based upon the "spellingbesluit "(besluit = "decree.") The spellingbesluit of 1996, instituting the nieuwe spelling, was drafted by experts co-operating with the Dutch-language Union (Nederlandse Taalunie.) The spellingbesluit is regulation for governmental and educational offices.
The Green Book, without official status, is nonetheless the "non-official official" reference.
It is produced by the Nederlandse Taalunie for use in Holland, Flanders, Suriname, and the Dutch Antilles. The governments in these regions determine how to conform to the specification.
The Green Book, of course, is always in modification, through addenda and in reprint. In 1994, the Taalunie determined that the spelling system would be amended every ten years. This would involve a new printing of the Green Book and a coordinated spellingbesluit. Presumably, changes in spelling rules would be minor, compared with those of the "nieuwe spelling" of 1996 the most important function probably being the treatment of words acquired in the interim.
The most recent Green Book reprint occured in late 2005; the minor changes in rules that pertain to this incarnation of Dutch became official in The Netherlands as of August 2006.
There has of course been debate and controversy about stipulations made in the spellingbesluit, and suggestion that government should not make rules about language.
But that's Dutch discussion, debate, and concensus.