Green open access is also called self archiving. Most traditional publishers, who make money from subscriptions, have a similar policy. The author may self archive/upload the preprints anywhere. A preprint is a DRAFT of a scientific paper that has not yet been published in a peer-reviewed scientific journal. For the accepted manuscript processing the publisher’s logo, the author may post it on personal websites. You have to study carefully the publisher’s policy, if the accepted manuscript will be posted somewhere else. Generally, the published paper is not allowed to be self-archived, unless the authors paid the golden open access fee.
You may find the self archiving policy of Elsevier at:
http://www.elsevier.com/about/open-access/green-open-access
the self archiving policy of Springer:
http://www.springer.com/gp/open-access/authors-rights/self-archiving-policy/2124
the self archiving policy of Wiley:
http://olabout.wiley.com/WileyCDA/Section/id-817011.html
More information can be found here: http://www.sherpa.ac.uk/documents/sherpaplusdocs/Nottingham-colour-guide.pdf
This article gives information of different Archiving Colors:
White: No self archiving allowed
Yellow: Can self archive preprint (draft)
Blue: Can self archive post-print (final draft)
Green: May self archive post-print and preprint