The green route allows authors additional options when selecting a journal for publication because authors may choose a subscription-based journal (or a journal that follows a traditional publishing model) as their journal, IF that publisher policy allows the author to place a copy of the article in an institutional repository (IR) eg. StFX Scholar or subject-based repository (eg. BioMed Central). Green OA typically asks authors to take the additional step of depositing works in a repository; this is also called "self-archiving." Note: you could also use a repository (if you have permission) even if the article is published open access in a journal (why would I do this? you might ask. Answer: It's just one more way someone could find your work!)
The gold route often implies that the work has published an article in an open access journal. True open access journals make all of their content to be available for free immediately. They often charge author fees to cover the costs of the publishing process called APC or Article Processing Charges. Authors should be aware that these fees are typically provided in USD. For journals that use APCs as a means to fund open access, these APCs are allowable expenses for Tri-Agency grants.
Hybrid Journals (these journals give you the choice of publishing OA for a cost)
You could pay an APC to publish an article open access in a hybrid journal. Hybrid journals are subscription-based journals (pay to read) but also give authors the option to pay a fee to make their article open access. Many would argue that hybrid journals are considered unsustainable and engage in a double-dipping business-model, because there are subscription fees that are paid by libraries for users to read content and there are fees paid by some authors to make content OA. These APCs are allowable expenses for Tri-Agency grants.