You can reference any combination that renders in the DOM. So in this case the css class and the element type you can reference. As it’s a link that likely has multiple associations to the class I would utilize an xquery that includes the parent object and then the a link and class, or the rendered text of the link if that is unique.
In general you can’t used derived class color information, but only what is rendered in the DOM. The drilled in view of the DOM that you have is what you can utilize to locate elements, if it isn’t in there then you can’t use it as the screen reader is literally reading the DOM.