Open Access: Green and Gold Open Access

Green open access (OA), also known as self-archiving, is repository-based open access. Green open access models relay on creators to take make a version their work freely available online in a subject repository or institutional repository such as Open PRAIRIE.

The benefits of green open access include making a copy freely available by avoiding the cost of author processing charges associated with gold open access.
The challenges with self archiving include the necessary author copyright retention required to share their work, publisher version sharing restrictions and embargo requirements.  

Gold open access (OA) model allows publishers to make articles available for free immediately on a journal's homepage. These articles are licensed for sharing and reuse via Creative Commons licenses.
Gold OA publishers usually charge an article processing charge (APC), which is typically paid through institutional or grant funding.

Published articles / works usually consist of three different versions when describing self-archiving in repositories is acceptable:

• Pre-print (or preprint)
  • Also known as the "submitted manuscript"
  • Version submitted (pre-refereeing)
• Post-print (or postprint)
  • Also known as the "accepted manuscript"
  • Author's peer-reviewed, final version without the publisher's journal formatting
• Version of Record
  • Journal formatted version
  • "Publisher's PDF"