Allow multiple terms per vocabulary to be included

I don't know if this exists already, but my site uses a single vocabulary for one of my content types (we'll call these "Tags"). I've defined all the tags that I want people to use (about 30 of them), and I want to be able to use Faceted Search to allow users to search for multiple tags inside this vocabulary. For example, if I have my tags as "Red", "Orange", "Yellow", etc. inside vocabulary "Colors", when I display my Faceted Guided Search page, it lists "Colors" as the heading, followed by all the colors, but when I click on one, I can't add additional terms from the same vocabulary to include in my search.