Colored coins are a class of methods for associating real world assets with addresses on the bitcoin network. Examples could be a deed for a house, stocks, bonds or futures. The technology could also be used to track and register intellectual property assets.
Through 2014/15 it was suggested that various coloured coin protocols could be of interest to banks and major financial institutions. This prediction came true in June 2015 when NASDAQ announced they were developing a system in partnership with blockchain startup Chain using the Open Assets protocol developed and utilised by CoinPrism and built on by Get Hashing. In late 2015 NASDAQ announced that the first ever trade had occurred using its new platform, Linq.
There are several competing implementations of the coloured coins idea, using differing methods, including those developed by CoinSpark, Colu and several built on the EPBOC protocol.