Counterparty may have Melotic and a built-in exchange in the Counterwallet but now colored coins have an exchange as well.
coinprisim announced today a new exchange with MasterXchange:
Today, we are extremely excited to announce a partnership between Coinprism and MasterXchange. Until today, exchanging colored coins has always been quite ad hoc. People have been running crowd sales using the crowdsale feature in Coinprism, and that works well for the initial sale, however many people have been asking about a secondary market.
This is now possible thanks to MasterXchange. They are now offering the ability to list any asset on their exchange. That will create an empty order book where people can go and place order for buying or selling the asset.
With the addition of a new exchange it is now possible to make trades among various coins and tokens. You can find more details and information on how to set up a new market read the latest blog post from coinprisim here.