Open Access comes in different colours. While we especially use the term green OA, gold OA and hybrid OA, other terms refine those broader terms.

This tip addresses some of the Open Access flavours.

Diamond Open Access refers to a scholarly publication model in which journals and platforms do not charge fees to either authors or readers. Diamond Open Access journals represent community-driven, academic-led and -owned publishing initiatives. Serving a fine-grained variety of generally small-scale, multilingual, and multicultural scholarly communities, these journals and platforms embody the concept of bibliodiversity. Definition taken from Action Plan for Diamond Open Access

Gold Open Access = Open Access publishing: Open Access journals provide immediate Open Access to the articles published. There is a large variety in business models and publishing methods. You can find an overview of peer reviewed Open Access journals in the Directory of Open Access Journals .

Green Open Access = self-archiving: publish in the journal of your choice, deposit a version of the publication (usually but not necessarily a post-print) in a repository and make it publically available in Open Access, sometimes after an embargo period set by the publisher. An overview of Open Access Repositories can be found on OpenDOAR. Publishers’ policies on (self)archiving can be found on SHERPA/RoMEO.

Hybrid Open Access: Some publishers allow immediate Open Access to some of their articles on condition that an ‘Article Processing Charge - APC’ is paid.  In such journals, two types of articles coexist: those freely accessible and others only accessible through a subscription. Although being mainly responsible for the recent rise in available Open Access publications, ‘hybrid Open Access’ doen’t take away subscription costs for those journals.

Platinum Open Access: Platinum Open Access is a model of scholarly publishing that does not charge author fees. The costs associated with scholarly publication are covered through other means, such as volunteer work, donations, subsidies, grants, etc.

Bronze articles are made free-to-read on the publisher website, without an explicit open license.

The difference between gold, green, bronze and hybrid is explained in this figure from CWTS

More Open Access terms are explained on the website of Open Access Belgium.