Embodiments of the invention provide systems and methods for brokering the purchase and/or sale of mixed-color glass and/or cullet, optionally over a computer network. In one embodiment, the broker facilitates the purchase and/or sale of three color mixed cullet between beneficiators, MRFs and/or glass plants, in order to supply, for example, glass plants with and/or allow glass plants to purchase desired quantity and/or quality (e.g., cleanliness) of cullet.