Here are some advantages to publishing open access:
Gold: Articles that are completely free on the publishers’ websites. When most people think of open access, they are thinking of gold open access. In many cases authors pay article processing charges that can range from $500 to $5,000. Example of a gold open access article in Digital Commons. If a gold open access journals has article processing fees, these fees are mandatory for an author's articles to be published.
Hybrid: Refers to traditional subscription-based journals in which the default is for their articles to be hidden behind paywalls. These journals provide authors with the option of paying fees to make their articles open access. If authors do not pay this this fee, their articles remain behind the paywall. Authors are only required to pay a fee to hybrid journals if they want their article to be open access. If they decide against paying the fee, their article will still be published, but remain behind a paywall. This differs from the policies of gold open access articles that require authors to pay article processing charges to have their articles published.
Green: This category which is also known as self-archiving provides authors with the option of uploading the full-text of published articles that are hidden behind paywalls to institutional repositories like Digital Commons.